**ATTENTION: If you have any concerns about removing a hot spark plug from an aluminum head, then you can also remove the plug when it's cool and heat it up in a toaster oven to 300 Deg F to perform the "hot" test. Never file down or sand Platinum/Iridium tipped plugs. "Hotter" spark plugs have a LONGER ceramic nose, and "Colder" spark plugs have a SHORTER ceramic nose. Using a slightly hotter plug can prevent fouling if your rings are worn and allowing excessive oil to accumulate on the spark plug's electrode. Thanks for watching! **For GREAT deals(Usually cheaper than EBAY) on AUTOMOTIVE TESTERS & TOOLS, neodymium magnets, Fidget Spinners, electronics, drones, automotive tools, household items, phone accessories, locksmith tools, & much more, please visit the link below and SAVE IT AS A BOOKMARK on your computer or smartphone to Banggood for future purchases. (Your purchase supports my channel!) All Items: bit.ly/2cgYr14 Flash Deals: bit.ly/2cb6CZB *Try these money saving coupon codes: Double12 or BFTOOL or affiliate6 or elec or elec1 or measure or HDWARE2 or WELDTOOL or ask if other codes are available!
Lawnmowers now use suppression plugs due to the Delphi fuel injection systems on Kohler and Vanguard. Specifically the NGK bpr4es and bprm4es as well the 5’s too. If not the 5 volt reference in the OBC will act wonky and cause problems in the injectors as well as the coils. Just a little info on the subject :)
Thanks Anthony! Be sure to rate thumbs up, share my channel with others, and look over my extensive video playlists for other great videos of interest to you.
First time I've seen a video that recommends testing when hot. This is super important, especially if you have a problem with missing when warm, or even just an intermittent miss.
You're welcome Kenneth! Many people like you have benefited from the info in this video. Thanks for watching! Be sure to share the video link with friends.
i have had two strimmers inat the same time both with poor hot starting and both had a plug that goes open circuit tip to cap when hot let it cool and the connection come back very nice to find a fault like this
This is seriously like the best video ever ! I was one of the "didn't know" people. Had no clue. I just switched spark plugs around and read codes. This is so much better. In my defense I'm Polish and I'm a girl so it's ok ;)
I used the information on this video to check a spark plug on a snow blower that was not starting and had been used once or twice. The 2nd measurement on the existing plug, from tip to the body of the plug, was not showing the results that were demonstrated in the video. I sprayed the other end where the spark should be coming and got inconsistent readings. I spent $1.90 to replace the plug, and the snow blower started immediately. Thanks for the service.
Glad the video helped Jim! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks ruclips.net/user/electronicsnmoreplaylists
When I had the pleasure of working with a great racing mechanic Mario Deliotti I showed him that a plug I had out of my Alfa Romeo sparked perfectly well out on top of the engine. He laughed at me, called me something in Italian, and told me to put it the spark plug tester. I did and it sparked ok looking through the inspection window. Now I turned up the air pressure ( the tester connected to the shop air line) and at 80 psi plus it hardly sparked at all. Put a new plug in the tester and that lit up like a Christmas tree at any pressure. As an electronics engineer I have never understood why this should be but it taught me that a low voltage meter test at atmospheric pressure is worthless. Don’t waste your time just replace the plug.
At a guess you sound as if you are in your twenties and dont appear to work in the motor trade. I have a vehicle in my own garage that has just this problem. I call BS on your "uncommon" statement, if only because you haven't have enough real world exposure to have encountered it.
I am 67 and have worked on most vehicles in an auto electrical capacity, It was just something that I surprised me as an electronics engineer, and later help me when I was designing electronic ignition systems.
Yes that is correct, the higher the air pressure, the harder a spark has to work to punch through it. However you do not need anything as elaborate as a pressure chamber to test spark plugs "under pressure". Simply open the electrode gap to one quarter inch and it will simulate it for you. If you get a good spark like that its good to go.
I can't speak for today but years ago Champion plugs came with a "booster gap" built into the internal connection from boot to tip. So the continuity check would read open circuit. The booster gap was there to make sure the available voltage was higher when the spark energy actually hit the tip. The idea was to be able to get a fast voltage rise at the tip despite some leakage to ground on the tip of the insulator.
Neat stuff. Every mechanic should have a heat gun (I've scored a few at yard sales so I can scatter them around the shop) and will try your method before and after heating up some spark plugs. A propane torch would also work and handheld thermometers are dirt cheap. To quick check plugs I shoved the end of a gas grill piezo igniter into an angled spark plug boot then ran some solid copper household ground wire around the shell so the ground contact on the igniter has a path to ground. (It normally grounds thru the gas grill body.) Wrap with electrical tape and you're done. Great for detailed arc observation without running an engine.
+Ob Fuscated - My heat gun is always moving around the workshop. Damn useful tool. :-) Neat trick with the piezo electric, I had an ignition simulator for testing but that's much better and small.
One small point to contend... I worked in auto part stores for over 15 years and have learned from reading the indexes that the reach of the ceramic on the combustion side of the plug is what controls the heat range. when the tip is recessed (protected from heat) it will be a cold plug. When the tip is projected into the combustion chamber, you will have more exposure to heat , and more ceramic material to hold the heat. Other than that your video is correct!
+john smith Hi John. This issue has already been discussed in the video comment area, and I also placed annotations in the video to clarify things I said. :-) Thanks For Watching!
First off, this is a valuable test. Over the years I've seen too many outboard and power equipment owners automatically throw new plugs into a motor expecting that to be the miracle cure. Ninety percent of the time, it isn't. But, I never thought of testing the electrical resistance of the center electrode, which would be the only real reason for failure outside of wear or breakage of the insulator.
Wonderful video. I put brand new plugs in my Ford Taurus, and it was missing really bad. Broke out my Meter, and two of the plugs were bad straight out of the box...Thank you, you saved my sanity !!
I just now found you channel. From reading comments on a project farm video. Holy cow do I have some watching to do. Glad to find you out there. Take care bud.
Thanks Tom! I have many videos on my channel that cover a wide range of subjects, so be sure to look over my video playlists below for other videos of interest to you, and most importantly share. You'll definitely enjoy my "Automotive" video playlist. ruclips.net/user/electronicsnmoreplaylists
Engines usually miss at idle or under acceleration/under load. Can either be a faulty spark plug/high tension lead & or coil pack. Some engines dont have high tension leads, but a coil pack for each spark plug. When you accelerate/more power, throttle butterfly opens increasing air supply into motor. Fuel injectors stay open longer allowing more fuel into motor. Therefore the ignition coil increases voltage for stronger spark under more demanding internal engine conditions. You can also test each individual high tension lead using ohms/resistance scale on your multi meter for either open circuit or very high resistance reading. As a rule of thumb, high tension leads should have anywhere between 7000 to 12000 ohms "per foot lenght" of high tension lead, (7K to 12 K scale). You can also test your ignition coil pack in a rather crude way, like a bush mechanic without any tools. Start your engine, let the motor reach normal operating temperature. Remove nut or bolt that secures each coil pack to the engine. With the motor idling, gently lift the coil pack slightly off one spark plug at a time so you can hear the sound of the spark jumping from the coil pack to the spark plug. Dont lift the coil pack too high off the spark plug. You will hear a specific normal spark rhythum. Your listening for an an irregular/abnormal spark sounding rythum. That will indicate a faulty coil pack. This test is limited to engines you can access the coil packs individually whilst motor is operational. Unfortunately some engines, wont permit this limited test. Be sure to wear rubber gloves & tools that are insulated. Cheers from 🇦🇺
Actually we use to check the resistance at the end of the Seal line during the manufacturing process. We also did dielectric test to ensure the bisque had no pin holes. We made millions of every brand plug on the market. No one brand was different from the others. I know some guy just crapped his pants to hear this, but Champion, Atlas, Prestolite, Autolite, Shell, Sears and others were made exactly the same with the same materials.
Genius Russell Ceramic clay is porse (having gap between Cristal) and carbon with fuet mixed oil gets penetrated during compressions created by piston , the cause of conversion to good conductor is the presence of same oil, so the Manufacturer should use cementing process of between grains gap . The easy , I obtained by soaking the center conical white clay with drops of Elfie (quick jointing liquid gum) that penetrates well in new, Un used spark plug. The life gets doubled with smooth performance. Try n see . my cont. +91 8853486995 ,
Bear Russell - I understand what you say perfectly. I always find quite funny the passionate discussions. French/American/ German/ cars is better than... something else. LOL :-) I worked for a very well known brand that among many others components, produced ignition coils. For anything American, French, German, English and so on, even Harley (motorbikes). Sometimes even part of the production line is the same... same workers under the same roof, etc. There are differences, but not where most people think. Surely not in the "brand". ;-) BTW the retail price is the most visible side of the story. LOL :-)
Well yeah, most products are marketed under various brand names even though they are manufactured by the exact same process. They all test the same, and operate the same. However, the issue occurs when the "Brand Name" is applied to the spark plug. The moment that the brand name "Champion" is imprinted on a sparkplug, its reliability is adversely affected.
Benny, hey I would like to chat a little if you find time. I knew what you mentioned above. Been indexing decades. usavetone@gmail.com I am an engineer re engineer of a few internal combustion systems and try chatting with guy's like you, thanks
Think about this? If the ohm reading is 1.5 ohms or more, I believe the spark plug is going bad. This is especially true when it comes to ohming out electronic fuel injector solenoids for Cummins Diesel Electronic Engines. Thanks for the tip on spark plugs. I never thought of your testing method on spark plugs. Please keep those videos coming!
I know you are dealing more with the electrical side of testing, but, don't forget to also look for signs of leaking gases around the insulator and signs of plasma staining on the insulator. Both are good indicators of ignition faults/wear and tear. I am hooked on your videos, great job.
When I change plugs on a motor (about 3 times a week) I will test 1 of them on a pressurized spark plug tester. It will blow your mind what passes and what fails. You can't tell by looking at or ohming out a plug. Under load a spark would rather jump a 1" gap in free air than a 0.040" gap at the electrode under 100 psi. pressure. Also, a loose boot on a plug will allow the spark to run down the side of the porcelain to ground.
Glad you enjoyed the video! Be sure to check out my extensive video playlists as well as my recent bicycle generator video, rate thumbs up, and share my channel with others. Thanks
As a Jet Mechanic I am glad you pointed out that the electrode could have cracks that and I might add that sometimes the cracks are not noticeable when the plug is cold but when the plug heats up the electrodes expand and causes a lack of Spark. It's funny watching this video I just went out and bought a tester this afternoon to test my Spark plugs in my new jet ski that I purchased that is not running and three mechanics have worked on and can't figure out why it wasn't running so I picked it up for 15,000 pesos in the Philippines with a trailer that's worth 25,000 pesos LOL because they couldn't get it running The motor itself according to the Spark plugs and lack of oil runs properly or did when it shut down so it hasto be a spark issue or electronics issue. Either way in a short period of time I will have ruled out any breaks in the electronic harness with the tester I purchased this afternoon and from there it can only be power pack which is as you note a sealed unit and must be replaced as a unit as a last resort. Absolutely ridiculous price of the electronic power pack in a jet ski GSX limited-edition SEA DO,,, $1000 plus shipping but it will be cheap if that corrects the problem considering I just purchased a jet ski worth 4000 American dollars for about $350 with a trailer that's worth more than what I paid for the unit and the trailer itself. Good upload and I will share it to Facebook.... not that any of the dweebs on my Facebook account would understand what you said LOL And I subbed your channel
my friend I have been living in the Philippines for five months now and have in a beautiful Apartment with a view of an ocean which is about 50 yards from my apartment and deck which makes my view in Florida look like a Manhattan tenement LOL I have a white sand beach and Miles beautiful coral right behind the house and I just purchase a jet ski that I am working on in order to travel around the Philippines via the ocean traveling method... go to my channel then look at all the videos of over 100 I have made of the Philippines is a beautiful place... once you get past the fact that the people are basically not very well educated but are pretty much friendly to the American dollar and to the people and have them so I am enjoying the lifestyle here immensely. To see where I live you can Google Wish You Were Here in ALONA BEACH and thanks for stopping by
Thanks for watching and subscribing! $1000 for the CDI/power pack.....what a bunch of criminals. I would try and remove all the potting material and swap out some components before I bought one. LOL . I would do a continuity test on every wire from point A to point B. My jet ski had one wire that corroded inside the insulation. Luckily I found it.
electronicsNmore that is precisely why I bought the meter a.k.a. to test each and every individual wire in every part of the harness From A to B. All it takes is a small crack in the insulation in a little bit of salt water and it will corrode internally as you well know. Plus if I showed you the video I made of the harness you would see that the three so-called mechanics peeled off some insulation about 3/8 of an inch long and twisted the wires together without cleaning the wire itself prior to twisting it which means it may not have any continuity whatsoever because they twisted oxidized wires together not knowing anything about oxidation because they are not mechanics in the true sense of the word. I however went out and purchased a nice little wire brush some flux 40/60 solder which is still legal in the Philippines I'm the properly spliced them together laterally like this supposed to be. Went to 12 stores in the last week looking for some heat shrink... and no one even knows what it is here in the Philippines so I purchased some 1/8 inch diameter clear hose used fish tank filters and after the joints are soldered I will put some black high heat silicone over the wire and slipped the tubing over that which I'm sure will be sufficient to keep it from getting wet... The machine ran perfectly until it was left unattended for a few months and when the man went to start it again it just didn't start so probably the electronics is not the issue and probably more like one of the three fuses I found that were blown?? Do you think? LOL We shall see,,, it's the 1494 in. cubic centimeter engine and if you look at it in the video I make this week you will say it looks like it just came out of the factory however when you look at all the cannon plugs you can see that the high-quality brass male and females are completely oxidized. So I will take my little files and drill bits and polish them up in an out. Between that and a proper soldering job and testing the wires themselves I should have ignition when I'm done with that. There are some heat sensors on the top of each head and also in the exhaust loop and I'm not sure if they will shut the motor down what I will check those as well and the tubing that goes to the sensors. This is my first jet ski and it didn't come with a service manual so I will look online I'm sure it's there but only purchase this machine three days ago and this is not my livelihood is now my hobby which I devote 10 hours a day to anyway LOL If I have any questions I will be sure to bring them up on one of your pages after I do some research on your videos if it is not covered somewhere that I can find? If I don't I still believe it is something a lot simpler than the power pack and that is my last resort and you are right it's highway robbery. Okay my friend thank you for returning my comment and best wishes to you from one mechanic to another. Michael
HoodwinkedbyanAngel Michael Fazio I am so glad I came across this video and y’alls ‘troubles’ after acquiring these sea-doos. I myself have been given one and it too was a ‘it ran perfectly when I shut it off but will no longer start’ scenario. 👍👍 I say “perfect!” as it too does not have any spark. Seeing as I love electronic/electrical type work I welcome the challenge...and hey, for the price?(free) I am ahead of the game already if it actually does need a part or two. Any recommendations where I should look first on one of these beasts? I have done two stroke ski-doos of all types so that part is pretty familiar, just not their watercraft. You say the ‘power block’ can/may be an issue?..I’m guessing it’s to do with leaking water internally causing it’s many quirks. Let me leave y’all with one recommendation when cleaning up corroded wires....you will thank me for this later..trust me. Whenever/where ever you have corroded wires needing to be reconnected and you find ‘sanding’ them or ‘scraping’ them with a blade don’t quite do it, try dipping them in muriatic acid from the hardware store. This product is used for cleaning and etching concrete in pools etc. NOW BE BERY CAREFUL WITH THIS STUFF!!! IT IS HIGHLY CORROSIVE AND EXTREMELY TOXIC!! USE IT WHERE THERE IS EXCELLENT VENTILATION AND KEEP CLEAN CLEAR WATER NEARBY TO NEUTRALIZE IT WHEN DONE. It takes only 10-20 seconds of dunking this in the acid and it’s done..clean. Quickly rinse it off with the clean water and dry it off completely. Do give it a few passes with the emery cloth or sand paper to get that brilliant copper shine back which makes it the easiest to solder. I know the good heat shrink is the best but I see not always available. Check for a product called ‘liquid tape’. It’s black in colour and smells a lot like contact cement. (😮 💡 😮☝️👍...did the lightbulb just come on? 👍😉) ...I believe if there is no liquid tape available, you may be able to improvise with the contact cement...I’ll leave that up to y’all to figure out 💡😉🤞👍 Spread this liberally on and over the newly soldered connection right onto the wire’s insulation so no water/moisture can penetrate it. Cover that with electrical tape to help stop any possible abrasions that may occur. Thank you kindly for any tips you may have for me and I hope mine will come in handy for you. With any luck it won’t take me long to repair it as up here in northern Canada, our ‘Sea-doo season’ is already awfully short as it is..from October to June the ice makes for some powerfully rough and cold boating on a sea-doo anyway. 😆😆😁😄🤣 All the best from a fellow mech. and watercraft enthusiast. 👋👋👋
In my opinion it's up to u or whoever is performing that task . Most mechanics should know how to test plugs . If u don't have time to test the plug then replace it . Or if don't have money to burn then test it. Do whatever works best for u .
yep the insulater is the bit at the electrode end of the plug, look under the electrodes, if the porcelain goes deep , it is a "hot" plug ie: there is a longer path hor the heat to escape to the metal body, if the central insulator is short and stubby, the heat escape path is short and effective, ie: plug runs 'cooler' ( a old plug) Cool plugs will oil up , hotter plugs will burn it off. ie: a champion n3 has a short insulator and a L7 has a long insulator
Thanks! I have an older Ford truck and it's starting to get bad gas mileage, nothing else wrong, I keep up with it really well, clean air filters, the oil changes, anything it's needed gets done. She does have high mileage but it's never sucked gas like this in the 8 years I've had her.
You're Welcome! Be sure to rate "Thumbs Up" and share. Also check out my other videos as well. Could be a loss of compression. Do a compression test. Any smoke in the exhaust? If not, could be dirty valves, or a fuel system problem. Spark plug wires/plugs can also contribute to a loss.
StormieinFlorida You might want to check the lambda sensor if your truck as one (or two). They tend to be forgotten and performance degrades with time.There's enough videos around to give you some insight on how to check it with a multimeter. Good luck ;-)
The type/brand of plug can indeed matter. I (and some friends) have only ever had good luck with NGK "V-power" plugs in our older cars (mostly V-8's). They last longer/run better,in my (our) experience. Some newer engines can be picky about the brand of plug as well. (I've even had good success using the NGK's in place of platinum plugs,in some newer engines.)
Hi, I never stated different types/brands of plugs did not matter, what I did say is the procedure outlined in this video works on all plugs. In my experience, using split fire / bosch platinum / NGK / autolite, I noticed no difference of performance with my personal water craft, cars, mowers, etc. I can probably switch out a plug that someone insists works better(without them knowing), and they would likely notice nothing. Thanks For Watching!
I see you talk about the resistor in this video as well. The resistor is to stop capacitance after firing of the spark plug. As the ignition system operates, the shielding in the plug wires builds up an electrical capacitance, ( just like a capacitor does). Once this capacitance is so strong, it'll jump the spark plug gap, this isn't good, so they build a resistor into the plug to bleed this stored electrical charge of slowly so that it does not jump the plug gap, and ware out the electrode tip prematurely. It can also lead to pre ignition. The electrically induced noise that you hear over your cars speakers is caused by the alternator frequency change when the capacitor goes bad in the alternator. The capacitor is an electric filter in the alternator, it performs the same job that the capacitor performs in an aircraft magneto p lead, it acts as a filter to filter out electrically induced radio noise. I'm not arguing, I'm just setting the info straight.
Sometime a plug can make a spark on the chassis and not in the cylinder head, its caused by the pressure, its a big factor in plug spark capability, and fooled plug can some time be recovered by burning the tips after cleaning it out with gas
You offer good info for the info you have learned and it is kind of you to share this info with the public. I am searching for remedy for a small engine's ignition deficiencies that brought me to your video. However- please do let me point out that during this video you explain the "heat range" of spark plugs can be determined by the length of the ceramic insulator that remains outside of the combustion chamber during a plug's operation when in fact the exact opposite is the truth. It is the plug's business end that is within the combustion chamber that has a longer or shorter measure of exposed insulation or not that determines the " heat range" of that plug. A small bit of misinformation may have consequence of temporary or possibly immeasurable value. Such value compounds when the misinformed do indeed spread to others what they believed to be the facts. You have had over 1.6 MILLION views of this video, it is that fact which motivated me to point out one important fact of operation.
To locate a bad plug just remove the plug coils one at a time while the engine is running. If the engine idlization doesn't become rougher and stays the same that means that plug is not contributing to the performance. You can try cleaning the plug if it's dirty, regapping and blowing out the socket port in the engine for debri.
Well , I have fully rebuilt a Stihl hedge trimmer due to low compression & fitted a new carby due to having a leaking main nozzle check valve, the ignition coil was also replaced due to having no spark. The spark plug isn't NGK but their electrode resistance is 5 K ohms for their resistor type spark plugs,the plug I have measures 9 K ohms which I am told is too higher resistance which can cause hard starting & rough running , in my case I have a no start issue meaning that despite the spark plug having spark when removed from the spark plug hole there may not be enough voltage at the electrode to fire the air/fuel mixture in the engine. While the spark plug ran a Briggs & Stratton 4 stroke lawn mower I noticed the motor was harder to start & didn't run as smooth (surged) at medium to low speed (idle) ,actually it stalled at idle with that spark plug. NGK suggests a maximum of 5 K ohms from the spark plug terminal to the centre electrode,I am off to the auto parts store tomorrow to see if they can supply me with a suitable spark plug.
i understand some plugs r cheap, but, we had a problem one year going thur champion plugs anywhere from two day to two an hour it was bad, anyway its nice to know how to be able to ck out if a plug is actually done, great video
Good Evening . Thank you very much for this video. I want to ask you this: all spark plugs - no matter what brand or if they are NGK all types NGK new ones when the readings show the same ohmic resistance? E.G. the NGK (BKR6EQU), (6002) new how much should it read? New I had not measured it but at 54,000 kilometers when I changed them and measured them they show (4.16) k. Regarding all this, what is your opinion? Thank you .
good info . never heard that before . I was going to comment on removing plugs from a hot engine , but you covered that too . I have 4 plugs I saved I'm going to test .
Very usefull for me......need some further advice on how to rule out a spark plug wire- some say that the lower the resistance the better the plug wire is....Magnecor says different and makes plug wires with very high resistance; so what do you advice me to choose? and of course, before choosing a new plug wire, what should I check to make sure I need to change it?
The resistance has nothing to do with how good the wire is. Wires are made for extremely low resistance, or high resistance. The insulation of the wire is what matters more. I suggest you contact the manufacturer to find out the suggested wire type to use. Thanks For Watching!
electronicsNmore Got it.....so here are some further questions: - since insulation is what matters, can I use some extremely good insulated ones like magnecor even though they have higher resistance over standard ones....? -manufacturer (Renault) doesn't say anything about their types... -how can I check a plug wire to see if its good or bad?
Likely have no problems with that wire. You can measure resistance across the wire and make sure the ohms per foot matches the manufacturers specs. Place the spark plug wire VERY close to the engine block at night and see if you observe any high voltage discharge(or corona) between the wire and the block. If you do, the insulation of the wire is degraded.
electronicsNmore Got it....instead of placing the plugs wires very close to the engine block- my wires are very short, cant get them close to engine- can I spray some water on them and see if discharges occurs?( using some of those "devices" used to clean windows set on "mist" to spray the water)
ncomplex1 Wires are just one part of the ignition system. Changing the type of wires without further modifications, or the need for them. Will not bring you any particular advantage, other than just spending money.But if your gonna replace it anyway, please make sure its up to at least manufacturer standards. ;-)
Thx for this video. What you are saying from 07:10 made me check and clean my spark plug thoroughly and now my scooter starts no problem! Great video. Thx again
In the past I measured the resistance of the new plug compared to the resistance of the old plug and gave the plugs a tolerance of 20% . That is how electronic resistors are ; with silver standard being 10% and gold standard being 20% . The plugs I use are cheap and when my cars computer starts tripping codes for bad plugs they are usually around 20% .
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If you have insulation tester, that’s better way to test the leak. It has high voltage of 500 or 1000 volts (most usual values, some have 5kV or 10kV) between the leads and measures the insulation resistance usually 500 or higher megaohms. Older models are available quite cheaply if they don’t have moren measuring algoritms. I found one in 30 euro. These are good if you measure HV cables too.
Most people don't know this because you don't need to do this. All you have to do is hold the threaded end against chassis ground to see if it sparks when cranking or running the engine. This will also indicate that power is getting TO the plug. If no spark you can repeat the test with a piece of bolt in the plug wire instead of the plug. You pointed to the wrong end when you indicated longer insulator means runs hotter. How far and thick it comes up at the spark end determines that. FYI, spark plugs practically never break apart in the middle, except possibly if you have trouble removing it and damage it doing so. Far more likely would be the tip has eroded away or is fouled too much, which might not be reflected at all in your direct contact meter ohm test. However this is all fairly silly. Once you've gone to the trouble of removing all the plugs (unless you have a specific cylinder misfire code), you might as well replace them. Spark plugs are not expensive in the grand scheme of vehicle repairs and far more often it's the hassle removing them in modern tight engine bays, not the expense that deters people from replacement, especially if it's a "V" engine instead of inline that has plug access at the top. As far as people claiming a plug is bad, that is very rare unless the plugs have so many miles on them that the owner already expected that it was time to replace them. I've been on multiple car forums for over a decade and am quite sure that spark plug paranoia is rare, except with specific engines known to, or evidence of excessive oil consumption which is noted by a drop in oil pan level.
Your method is not a sure way to test the plug. I outlined all tests in this video which have been proven to rule out the spark plug as the cause of engine trouble. You must learn to read PINNED comments before posting comments. Lastly, do it your way if you don't like my method. I never force anyone to do anything on this channel.
Some might remove 4 ngk plugs on a motorcycle (which are easier to do depending on the setup) and pay $10 or more to replace them. Thats at least a 6pack ! Y not clean them and reinstall if they are good?
Stinky Cheese. I just replaced 18 spark plugs on a lycomin R 680 radial. Most the plugs had a resistance of 9.68 m ohms, that's 968,000 ohms of resistance, 5,000 is the point of replacement. Huge difference, these plugs still fired at low pressure in the plug spark tester, but when the pressure is increased in the tester to simulate the high cylinder pressures, the plugs stop firing, those are bad plugs. You can test your plugs all you want like you have explained, but it means nothing if they spark. Because there are no cylinder pressures acting on them to reviel that there faulty. That's why an engine alot of time will idle fine, but when you accelerate and open the throttle valve, the pressure in the cylinders increase and the plugs start to miss fire, creating a loss of power. You need your multi meter set to ohms, 1000 to under 5000 ohms is good, and the SPCT spark plug tester to simulate cylinder pressures while sparking the plug. That's how you test plugs. That will reveal bad plugs.
I agree. Been working on vehicles for 35 years and what you're saying is true. Aircraft plugs are worth this test because they cost about $40 each, low end. Thanks for sharing.
HI, good video....I have a question on my champions spark plug UL77V when I measure the resistor like you did...using an ohm meter Fluke 60M from the center of the electrode to the center tip the reading for all is over 60M is this normal reading ? the test was perform on a bench (cold) Thank you
Mo Mo I do not know that particular meter, but if you are getting results that do not match what I showed in the video, then the plug is likely bad. You should have no reading between the center electrode and metal threaded body of the spark plug using the highest ohms range on your meter. Perform all tests hot and cold to rule out the plug. Thanks For Watching
Hey good vid ..I once had a issue with a plug that was fine, sparked fine ,but when under compression would not function at all..it just about wrecked me.
This procedure only test for one failure mode. There are several other failure mode. Think of cracks in the insulator. Never remove a spark plug from a hot engine. As a rule: when you take a plug out, just screw in a new one. And do pay attention to the recommended installation procedure: - use of lubricants (many plugs do not require lubrication) - way of torquing (depends on seal used) - use a proper spark plug socket or risk cracking the insulator.
Actually it tests (2) failure modes. An annotation was added which explains how to test the plug heated up to rule out any insulator cracks or heat related issues. Good ole toaster oven set for 300 deg F.
good vid and info, I am old and have done many types of mechanics my whole life , I wasn't aware of this...thanks for taking the trouble to share friend...God bless...doug
Nice name. :-) Thanks for watching! Be sure to check out my extensive video playlists below for many other videos of interest to you, and most importantly share my YT channel on social networking sites. ruclips.net/user/electronicsnmorec/playlists
Many thanks for the presentation. More, and more frequently, resistor plugs are being used in small engines, Does that resistor further increase the spark's voltage across the terminals ?
How do we know what reading for spark plugs should be for year make and model of vehicle? & Also the readings for other electrical parts like ignition module etc?
Hi Ramon. You can look up the spark plug number online for more detailed specs. Thanks for watching! Be sure to rate thumbs up and share my channel with others..
very good gentleman, I am driving 1000 cc suzuki cultus, four cyclinders, It is 2012 model, EFI. The engine started to miss on CNG and a repairman changed a sensor on carbeurator. but later I started to feel misfire or sometimes light blasts in left cylinder. I removed that plug and put it into right side cyclinder, but then I felt misfires in right side cylinder. I removed it and purchased a new one, however your tutorial was realy very informative, now I will check the removed plug, wether it was out of order, however it was newly installed. There was a loose connection which not only damaged the wire but also damaged the plug.
great video very informative I've known about the lean rich hot cold what the pulg is telling you about the engine and fuel delivery thanks for taking the time to share your method of testing
What is the range of KΩ you are supposed to get with automotive spark plugs with an internal resistor? You said roughly 6.3KΩ but I need to know the exact min and max! With 2 pin COP ignition coils it's: ▪︎ 1.0Ω or less for primary coil ▪︎ 6.0-8.0 KΩ for secondary coil I would appreciate it if you can tell me the resistance range for a standard copper E3.48 DiamondFire spark plug or any standard 98%Copper with 2%Nickel spark plugs and Platinum or Iridium if there is a difference
Doug, thank you for your concise and informational video. A couple of questions...is it possible to test plug for spark while it is still in? Also, my specific application involves a non-working leaf blower, therfore i cannot test a "hot" plug; does that matter? My guess is that there are lots of people who are testing their plug because it can't "get" hot! Thanks again. dc
Excellent information, I was just wondering when testing the resistance of a lawn mower plug how does a resistance test work on a lawnmower plug that has NO resistor? my understanding is that resistance is load from a device or a restriction of current flow by the use of an actual resistor and a NO resistance reading is ZERO OHMS so you would not be able to get a resistance reading from a NON resistor plug of course so to tell if a lawn mower plug is defective you will just get the ZERO OHMS reading yes? what would the OHMS result be on a defective lawnmower plug then? NOT higher than ZERO I would imagine because there is NO resistor, i'm confused.
+Thetrucky69 If the spark plug has no resistor, then the ohms reading should be very low(zero or close to it). When a mower plug is faulty, it will fail the high resistance(Mohm) test. Also test the plug after it is heated up to 300 deg F in a toaster oven for 5 minutes. Be sure to handle the plug with gloves, and place it on a thick bottom glass (turn the glass upside down)for testing. Do not touch the spark plug probes or spark plug while testing!
+electronicsNmore I am still confused about a faulty lawn mower spark plug failing the high resistance test as a NON resistor plug should ONLY be expected to show a very low OHMS or ZERO OHMS reading anyway but you don't need to reply. I am not trolling mate as I just like to learn but don't want to irritate you. Excellent tutorials mate I am subscribed cheers.
Thetrucky69 The LOW resistance test is between the electrode tip and end of the plug where you attach the wire. For a mower, that is usually a reading very close to zero ohms. The HIGH resistance test is between the end of the plug where you attach the wire and the body that threads into the block.
I have heard different values with ohms readings (multimeter) for small engine spark plugs (mower, snow blower, etc.). Can you set it straight for me? Some say a good spark plug should read 500 to 5000 ohms. Others say 4000 to 8000 ohms. And still, others say 5000 to 15000 ohms. Which is it? Or, is there another standard of values to use?
I have a snowmobile that eats plugs like smarties. Sometimes only get a couple minutes out of them. The plugs test good but will not spark. I've even tried them on different machines. The snowmobile is a 3 cyl 2 stroke. It's not the same plug that goes bad either. I'm very confused. This system fires all 3 plugs at the same time with 3 separate coils. Any Idea what would cause a new plug to blow but still test good?
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Muy bien ilustrado,teniendo en cuenta que los manufactureros NO recomiendan quitar las bujías hasta que el motor se enfrie pero, entiendo que al hacer las .pruebas en frió al conectarlas otra vez para probarlas calientes, las podría dejar menos apretadas para que no vaya a ajustarse mucho da~ando así la rosca estando el motor caliente y así hacer ambas pruebas, Thank's.
To be for use one would need to know the acceptable resistance of the plug in hand. I dont know what mine is supposed to be. Looking at your tests I could come back with anything from 0 ohms to Kohms on a plug, but unless i know what its resistance IS then i cannot use this test to any effect. Any rules to apply here? Thanks
Hi,Thanks (what's your name?), Nice video. Just a couple of questions...how do I tell if a plug has a resistor or not from the outside? (from looking at it?) and there was text saying don't sand platinum plugs but didn't tell us why? Thnx again, Bj
I'm Doug. You can tell if the plug has a built in resistor by the part number which usually contains an "R" at the end, or you have to use the DMM to test it to find out. Platinum plugs are "self cleaning" plugs. There is a VERY small dot of platinum on the ceramic tip, sanding it will damage the plug. No need to clean those plugs. Thanks For Watching!
Can we conduct this test for platinum plugs? I was told not to touch the electrode of a platinum plug because they're very sensitive and will likely be damaged.
Great video, concise and thorough and not boring as some of the educational vids on youtube are, these are important facts that anyone mechanically minded should know and in case they forget its good to come back and have this as a reference. Thanks! Big thumbs up :)
Allow the engine to cool down to a room/shop temperature. (most applications). Attempting to remove the spark plugs from a HOT engine may cause the spark plug threads to seize, causing damage to the cylinder head threads. ... Also contaminated threads may prevent the proper seating of the new spark plug.
What I am enquiring about is where I place one DMM lead on one end of the porcelain and the other lead at the other end of the porcelain.Bear in mind that there is no contact to any metal surface.
For the 1st test in the video(measuring plug resistor), use the 20K range, lower left, for the second test using NO hands, use the 2000K setting. Just to let you know, that range is not that high. For a reliable test you need a DMM with at least a 10M range.
+electronicsNmore I have 4 iridium plugs for my yamaha. Cyl 1-2 have a value of 4000 ohms, cyl 3 has a value of 7800 ohms and cyl 4 has a value of 3700. Could that cause some rough running (misfires and loses power) at higher rpms? (The plug with a high value is also black compared to the other ones that look normal. (no oil residue, just black in colour) The coils check out OK.
Love you clear concise no nonsense delivery and relevant annotations. Do you only do the cold and hot tests to rule out starting/performance problems that are happening within the maintenance schedule or to also extend the maintenance schedule of spark plugs. Would you then oppose the recommendation of replacing all your spark plugs at the same time? Thanks.
ourlegacy The cold test is usually good enough(At least for me), but to be 100%, you should do the hot test. Replacing one faulty spark plug can make the engine run great again, but usually you would replace all the plugs at the same time. Thanks For Watching!
Oh! My bad !! I do have a NGK BPMR7A spark plug for my hedge trimmer , the Briggs & Stratton lawn mower has the Champion plug which is a non resistor type, I compared the resistance between the Stihls spark plug which is actually 9.53K ohms & my dads Honda leaf blower which has a 10.5 k ohm resistor inside of it & runs good so I need to confirm why the readings for both NGK spark plugs are at around 10 K ohm whereas others I measured which are for a Honda lawnmower & other GM spark plugs (Denso) measure at between 3 - 5 K ohms so I am looking for an explanation for that ,is the BPMR7A spark plug supposed to measure at 9.53 K ohms?
how about a bosch super 4 i've found a faulty one that says its (connector to tip ) 4.95 ohms resistance, but it also has 980 on diode check, does not spark others that do work are in rang off 5.48 to 5.66 ohms and have a good spark, no shorts to shell on any of them have you come across this before. ?
yeah its in K its auto setting multimeter cat3. sorry for delay been bizzy. its the only one of 4 that has a diode reading, changed it for a spare one i have and the engine runs now without missing, but ordered a new set. just dont get how its coming up with a diode reading.
From my experience working on bike engines:(1) Does it have NGK written on it??(2) Is it more than 3 months old??(3) Is the plug black??(4) Replace the plug with a better made brand (or just replace with another NGK plug if you enjoy frequent spark plug issues).
+Zyggiespace I own and work on a lot of 1970's 2 stroke bikes running more than 9:1 compression ratio and have found that NGK plugs don't like (A) high compression ratios and (B) 1970's 2 strokes that tend to "buzz" a bit when on long trips. The faults that is typical is that after 15 to 20 miles of open road high speed riding first the bike starts to cut out occasionally on one cylinder (or starts to judder on a single pot motor) when the throttle is opened up. Then the plug just stops sparking and the rider pulls over and suspects (wrongly) that something like a wire has come loose. After much fiddling and faffing about the fault has apparently cleared itself (the bad NGK plug has cooled down) and the engine starts and runs perfectly..... for the next 15 to 20 miles and the whole thing starts again. If I had a beer for everytime I've had this happen to me or friends over 35 years of riding motorcycles I'd be drunker than an alcoholic trapped in a brewery. I surmise, from testing the plugs before and after they've cooled down with a continuity tester, that the problem is that the metal rod though the porcelane between the electrode and pip on the top of the plug moves and looses electrical contact when the plug overheats. Once cold the plug returns to electrical continuity until overheated once more. Breaking open theprocelane on an NGK plug reveals that they are unconventional in the use of a copper rod rather than the more traditional steel or iron rod (as use in Lodge plugs and others) which might be the cause of the problem in that copper expands differently to steel and iron, causing it to break contact when the plug overheats. 2 stroke also run a lot hotter than 4 stroke motors, which doesn't help.
I do know that the Arctic Cat 1100 turbo comes equipped with NGK MR8AI-9 plugs and those have held up to a substantial amount of boost pressure. That might have been an issue with them heating up and breaking in the past, and using a copper core (I have broken some on accident) but they dont use that anymore, Also, todays four stroke engines produce much more heat than two strokes.
+Zyggiespace My local motorcycle repair shop owner confessed that the reason why NGK is the only brand they carry is because they have a higher turnover than when they stocked Nippon Denso, Champion, etc. and having worked in a motorcycle dealership in the recent past, the same was true with that place too. The repair shop owner said that when he sold somebody a plug they didn't need to replace it for more than a year or even two years. By comparison he can guarentee that a customer will need to replace an NGK plug per cylinder every 4 to 6 months on a everyday use commuter bike. He even spent 2 wasted hours trying to sort out an ignition problem on a customer's bike during a service only to find out that the brand new NGK plug he'd fitted from stores was dead as a Dodo. He reckons that QA has gone downhill over the years with NGK. Here in the UK NGK is the only brand that every motorcycle shop carries (good turnover!!) so try finding ND, Bosch, Brisk, Champion and as for Lodge, by sheer luck after searching the internet due to the high price. (I've had a set of Lodge plugs last through 3 bike engines over 8 years, but for what I paid for them, I'd expect no less).
+Andy Reid back to your previous comment. I'm not sure what ratio you mix the gas/oil in these 1970s two stroke bikes. or if they run an injector pump. but I see a great increase in plug life, regardless of brand, if the oil is leaned out to a certain point. for example. 32:1 leaning it out to 40:1 or even 50:1. while gaining some slight performance
Can we determine wether he spark plug contains a resistor inside or not by its length. For example, if the spark plug is short that means probably it does not contain a resistor inside?
So if the multimeter checks the plug as ok, it means with 100% that the plug really creates an actual spark? I do not need to check this by starting it unplugged from the piston chamber to visually see the spark? This test is enough?
well , the test meter , whikle checking ohms of center electrode, might not tell you about any crack in ceramic, with which centeral electrode is coated. But, when such a plug is installed, the powerfull current might jump through crack, and engine might misfire, or malfunction due to increasing heat.
Is it still ok if my sparkplugs with resistor doesn't reach the 6,000 ohms reading and only has more or less between 4,000 - 5,000ohms is it still ok to use? Thanks
Thanks for this insightful video I am currently having an engine problem i.e. poor idling performance and I am glad to learn about this test. To make a long story short I have replaced the old spark plugs with a new Bosch brand but still experience loss of power. what could the probable cause be ?
Hi, What you stated is exactly why I uploaded this video. You bought all new plugs that you did not need. Are you located in the USA? Many auto parts stores will allow you free use of their automotive computer code scanner. Using the code scanner will let you know if any problems are detected. If no code scanner is available, or the scanner shows no problems, then it could be many things. Clogged fuel injectors, dirt carb, bad timing, etc. Thanks For Watching! Be sure to share, and also check out my video playlists.
Thank you Sir Bad ignition timing seems a good guess ! It all started with sporadic misfiring at low RPM a few days ago. Upon speeding up, everything seemed OK. In the process of unscrewing the old spark plugs, the ceramic insulator shattered and a small bit fell into the engine cylinder (combustion chamber) I suppose this was an awkard mishandling on my own or it might well be that the spark plug was already worn out and cracked under extreme heat stress. We managed to partly retrieve it with a vacuum cleaner. When the engine was restarted, an ominous sound was heard which quickly disappeared after running the engine for 15 minutes at 1500 RPM. I suppose the engine managed to digest (desintegrate) and expell into the exhaust pipe whatever bits were left. Everything was back to normal however after travelling 15 kilometers a severe loss of power was observed. I will keep you updated as things unfold. The computer screening code you are talking about is called here a diagnostic suitcase. The car make is Ford Mondeo... Greetings from France
Glad you enjoyed it Jim! Be sure to rate thumbs up, subscribe, and look over my extensive video playlists below for many other videos of interest to you. Taking one minute to share a link to my channel with others on social networking sites would be greatly appreciated. Thank you ruclips.net/user/electronicsnmoreplaylists
I put plugs in my acuara I believe they were E3 the tip screws on and off. Do not know why. However if get plugs like this put lock tite on them. The tips got loose and the code was no help in tracking it down. I should have checked the plugs. But I did not. $100 later from the dealer felt like an idiot. I am sharing so you can be aware of it. Other than that I did not have any problem with the plugs. Thanks for sharing this video learned alot.
Using a wire brush to clean the electrode and the anode creates a conductive coating that will short the current path. It is fool proof to use a spark plug sandblaster and they do not cost much at Harbor Freight if you have a decent output compressor but if you use a pancake compressor it might not work so well. Wire brushes do not like park plugs.
I have E3 3.40 spark plugs and when testing one I get 5.65 on one of them and the other I get 7.75 on a cold test with the meter set to 20K ohms. Is this normal? I seem to hear a tinging noise on WOT after doing an ignition tuneup.
@@electronicsNmore thank you. Was thinking about that about the fuel. It's very faint sound but it's still noticeable. I will also run the car without the dog house to get a better hear on it. Also I just check the other side of the engine and one of those spark plugs came out to 4.45 ohms If I remember correctly. I have a 351 Windsor V8.
The temperature range is variable by the length of the insulation around the electrode tip to where it connects to the body and not the length of the top of the plug, the shorter the insulation the colder it will run also insulation break down is a common failure, tiny tracts of carbon impregnate the crack and will earth down to where the insulator connects to the plug body.
In the video I stated that a longer plug(longer ceramic insulator) is hotter, which is accurate. The rest you mentioned is accurate as well, which is why the high resistance 20 meg test is used. Thank For Watching.
electronicsNmore No, I think Mentorcase is right - you were pointing to the UPPER part of the ceramic insulator being longer, he's saying it's specifically the LOWER tip part having a longer exposed part that makes it a hotter plug. This latter part is the where the heat of combustion is concentrated and a longer exposed ceramic tip gets hotter and burns off the carbon better. The length of the upper ceramic part has nothing to do with it since it's above the metal heat sink part of the plug. See www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp for example.
Much easier to remove the plug , ground it and check for spark while cranking engine, coil is easy to test and doing it this way can diagnose improper gap issues
I measuring the spark plugs for my 1999 Miata. Three of the spark plugs measures around 5.2k ohms. There's one that measures 7.2k ohms can I conclude that one is bad?
All plugs should be "similar". The more important test is the "High Resistance" test from the center electrode to the metal body. If it passes that test, you're likely OK.
In my opinion: If you have a power gap plug or silicon resistor type your won't get any readings until a large amount of voltage goes through it. Not all plugs have the same type of resistor or have a straight through conductor.
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**ATTENTION: If you have any concerns about removing a hot spark plug from an aluminum head, then you can also remove the plug when it's cool and heat it up in a toaster oven to 300 Deg F to perform the "hot" test. Never file down or sand Platinum/Iridium tipped plugs. "Hotter" spark plugs have a LONGER ceramic nose, and "Colder" spark plugs have a SHORTER ceramic nose. Using a slightly hotter plug can prevent fouling if your rings are worn and allowing excessive oil to accumulate on the spark plug's electrode. Thanks for watching!
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Lawnmowers now use suppression plugs due to the Delphi fuel injection systems on Kohler and Vanguard. Specifically the NGK bpr4es and bprm4es as well the 5’s too. If not the 5 volt reference in the OBC will act wonky and cause problems in the injectors as well as the coils. Just a little info on the subject :)
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what is the best spark plugs to use in a 98 ford explorer 4.0 sohc v.6
Clear and articulate, no nonsense, good old common sense, no annoying hard rock or ricky ticky music to distract. Well done. Keep up the good work.
Thanks Anthony! Be sure to rate thumbs up, share my channel with others, and look over my extensive video playlists for other great videos of interest to you.
Can we have an article about cable resistance/airgap resistance, the latter mainly in America.?
Indeed. This gentleman does commendable, thorough work and actually USES his brain... Something that, very sadly, has become very rare these days.
First time I've seen a video that recommends testing when hot. This is super important, especially if you have a problem with missing when warm, or even just an intermittent miss.
This was very relevent for me, precisely illustrated the issue I was having, and here it's 2020. Thanks for keeping this on RUclips.
You're very welcome! Always nice to have viewers from Down Under! Be sure to share my channel with many others. Thank you!
Thanks for this video, I diagnosed a bad plug (which seemed totally fine), this got my generator running for $3 and made a lot of headaches go away.
You're welcome Kenneth! Many people like you have benefited from the info in this video. Thanks for watching! Be sure to share the video link with friends.
i have had two strimmers inat the same time both with poor hot starting and both had a plug that goes open circuit tip to cap when hot let it cool and the connection come back very nice to find a fault like this
This is seriously like the best video ever ! I was one of the "didn't know" people. Had no clue. I just switched spark plugs around and read codes. This is so much better. In my defense I'm Polish and I'm a girl so it's ok ;)
I used the information on this video to check a spark plug on a snow blower that was not starting and had been used once or twice. The 2nd measurement on the existing plug, from tip to the body of the plug, was not showing the results that were demonstrated in the video. I sprayed the other end where the spark should be coming and got inconsistent readings. I spent $1.90 to replace the plug, and the snow blower started immediately. Thanks for the service.
Glad the video helped Jim! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks
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When I had the pleasure of working with a great racing mechanic Mario Deliotti I showed him that a plug I had out of my Alfa Romeo sparked perfectly well out on top of the engine. He laughed at me, called me something in Italian, and told me to put it the spark plug tester. I did and it sparked ok looking through the inspection window. Now I turned up the air pressure ( the tester connected to the shop air line) and at 80 psi plus it hardly sparked at all. Put a new plug in the tester and that lit up like a Christmas tree at any pressure. As an electronics engineer I have never understood why this should be but it taught me that a low voltage meter test at atmospheric pressure is worthless. Don’t waste your time just replace the plug.
Never had the test fail. Your situation was highly uncommon.
At a guess you sound as if you are in your twenties and dont appear to work in the motor trade. I have a vehicle in my own garage that has just this problem. I call BS on your "uncommon" statement, if only because you haven't have enough real world exposure to have encountered it.
I am 67 and have worked on most vehicles in an auto electrical capacity, It was just something that I surprised me as an electronics engineer, and later help me when I was designing electronic ignition systems.
Yes that is correct, the higher the air pressure, the harder a spark has to work to punch through it. However you do not need anything as elaborate as a pressure chamber to test spark plugs "under pressure". Simply open the electrode gap to one quarter inch and it will simulate it for you. If you get a good spark like that its good to go.
That's a good tip but unfortunately these were Lodge 2LH plugs with the four point electrodes.
I can't speak for today but years ago Champion plugs came with a "booster gap" built into the internal connection from boot to tip. So the continuity check would read open circuit. The booster gap was there to make sure the available voltage was higher when the spark energy actually hit the tip. The idea was to be able to get a fast voltage rise at the tip despite some leakage to ground on the tip of the insulator.
Neat stuff. Every mechanic should have a heat gun (I've scored a few at yard sales so I can scatter them around the shop) and will try your method before and after heating up some spark plugs. A propane torch would also work and handheld thermometers are dirt cheap.
To quick check plugs I shoved the end of a gas grill piezo igniter into an angled spark plug boot then ran some solid copper household ground wire around the shell so the ground contact on the igniter has a path to ground. (It normally grounds thru the gas grill body.) Wrap with electrical tape and you're done. Great for detailed arc observation without running an engine.
+Ob Fuscated - My heat gun is always moving around the workshop. Damn useful tool. :-)
Neat trick with the piezo electric, I had an ignition simulator for testing but that's much better and small.
Let me make sure U hold heat on the plug till you read 300 degrees for a hot plug correct?
One small point to contend... I worked in auto part stores for over 15 years and have learned from reading the indexes that the reach of the ceramic on the combustion side of the plug is what controls the heat range. when the tip is recessed (protected from heat) it will be a cold plug. When the tip is projected into the combustion chamber, you will have more exposure to heat , and more ceramic material to hold the heat. Other than that your video is correct!
+john smith
Hi John. This issue has already been discussed in the video comment area, and I also placed annotations in the video to clarify things I said. :-)
Thanks For Watching!
THis is hands down the best video on the subject Sir. Nicely done fella.
Glad you think so!
Hi Mr.Electronics ,man you are from the future ,you are so knowlegable man I admire you ,just brilliant.
:-) Be sure to share my channel with many others. Thanks!
I bought the same tester today at auto zone it's not $5 anymore but $8.99. Bit after seeing yours had to have it. Thanks for the tips.
Glad you enjoyed the video Robert! Be sure to check out my automotive/mechanical video playlist, and product review video playlist. Thanks
First off, this is a valuable test. Over the years I've seen too many outboard and power equipment owners automatically throw new plugs into a motor expecting that to be the miracle cure. Ninety percent of the time, it isn't. But, I never thought of testing the electrical resistance of the center electrode, which would be the only real reason for failure outside of wear or breakage of the insulator.
Wonderful video. I put brand new plugs in my Ford Taurus, and it was missing really bad. Broke out my Meter, and two of the plugs were bad straight out of the box...Thank you, you saved my sanity !!
Gary Scott Fischer You're welcome. Be sure to check out my other videos, share, and rate Thumbs Up. Thank You!
I just now found you channel. From reading comments on a project farm video. Holy cow do I have some watching to do. Glad to find you out there. Take care bud.
Great to hear! Thanks for watching
came here after watching project farm, both of you are great and ill be sharing your videos too, well done videos!
The best video on the subject I've seen. Been working on bikes all my life and learned something new. Thanks
Thanks Tom! I have many videos on my channel that cover a wide range of subjects, so be sure to look over my video playlists below for other videos of interest to you, and most importantly share. You'll definitely enjoy my "Automotive" video playlist.
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Better off to use an insulation tester as used for electrical installation work set at 1000volt scale /me Retired elecrician
Engines usually miss at idle or under acceleration/under load. Can either be a faulty spark plug/high tension lead & or coil pack. Some engines dont have high tension leads, but a coil pack for each spark plug. When you accelerate/more power, throttle butterfly opens increasing air supply into motor. Fuel injectors stay open longer allowing more fuel into motor. Therefore the ignition coil increases voltage for stronger spark under more demanding internal engine conditions. You can also test each individual high tension lead using ohms/resistance scale on your multi meter for either open circuit or very high resistance reading. As a rule of thumb, high tension leads should have anywhere between 7000 to 12000 ohms "per foot lenght" of high tension lead, (7K to 12 K scale). You can also test your ignition coil pack in a rather crude way, like a bush mechanic without any tools. Start your engine, let the motor reach normal operating temperature. Remove nut or bolt that secures each coil pack to the engine. With the motor idling, gently lift the coil pack slightly off one spark plug at a time so you can hear the sound of the spark jumping from the coil pack to the spark plug. Dont lift the coil pack too high off the spark plug. You will hear a specific normal spark rhythum. Your listening for an an irregular/abnormal spark sounding rythum. That will indicate a faulty coil pack. This test is limited to engines you can access the coil packs individually whilst motor is operational. Unfortunately some engines, wont permit this limited test. Be sure to wear rubber gloves & tools that are insulated. Cheers from 🇦🇺
Actually we use to check the resistance at the end of the Seal line during the manufacturing process. We also did dielectric test to ensure the bisque had no pin holes.
We made millions of every brand plug on the market. No one brand was different from the others.
I know some guy just crapped his pants to hear this, but Champion, Atlas, Prestolite, Autolite, Shell, Sears and others were made exactly the same with the same materials.
Genius Russell Ceramic clay is porse (having gap between Cristal) and carbon with fuet mixed oil gets penetrated during compressions created by piston , the cause of conversion to good conductor is the presence of same oil, so the Manufacturer should use cementing process of between grains gap . The easy , I obtained by soaking the center conical white clay with drops of Elfie (quick jointing liquid gum) that penetrates well in new, Un used spark plug. The life gets doubled with smooth performance. Try n see . my cont. +91 8853486995 ,
Bear Russell - I understand what you say perfectly. I always find quite funny the passionate discussions. French/American/ German/ cars is better than... something else. LOL :-)
I worked for a very well known brand that among many others components, produced ignition coils. For anything American, French, German, English and so on, even Harley (motorbikes). Sometimes even part of the production line is the same... same workers under the same roof, etc.
There are differences, but not where most people think. Surely not in the "brand". ;-) BTW the retail price is the most visible side of the story. LOL :-)
Y7
Well yeah, most products are marketed under various brand names even though they are manufactured by the exact same process.
They all test the same, and operate the same.
However, the issue occurs when the "Brand Name" is applied to the spark plug.
The moment that the brand name "Champion" is imprinted on a sparkplug, its reliability is adversely affected.
Benny, hey I would like to chat a little if you find time. I knew what you mentioned above. Been indexing decades. usavetone@gmail.com I am an engineer re engineer of a few internal combustion systems and try chatting with guy's like you, thanks
Think about this? If the ohm reading is 1.5 ohms or more, I believe the spark plug is going bad. This is especially true when it comes to ohming out electronic fuel injector solenoids for Cummins Diesel Electronic Engines. Thanks for the tip on spark plugs. I never thought of your testing method on spark plugs. Please keep those videos coming!
Straight up and to the point, clear speech, no bullshit. One thumbs up for you!
caliwebman Thanks Cali. Please share my channel.
caliwebman, How would shit from a bull get into a spark plug?
I know you are dealing more with the electrical side of testing, but, don't forget to also look for signs of leaking gases around the insulator and signs of plasma staining on the insulator. Both are good indicators of ignition faults/wear and tear. I am hooked on your videos, great job.
Ttttttttttþttttttttttttttttttt
When I change plugs on a motor (about 3 times a week) I will test 1 of them on a pressurized spark plug tester. It will blow your mind what passes and what fails. You can't tell by looking at or ohming out a plug. Under load a spark would rather jump a 1" gap in free air than a 0.040" gap at the electrode under 100 psi. pressure. Also, a loose boot on a plug will allow the spark to run down the side of the porcelain to ground.
That may be true, but the test does work and never failed me.
great video. good info and you are not talking about yourself like a lot of youtubers do.
Glad you enjoyed the video! Be sure to check out my extensive video playlists as well as my recent bicycle generator video, rate thumbs up, and share my channel with others. Thanks
As a Jet Mechanic I am glad you pointed out that the electrode could have cracks that and I might add that sometimes the cracks are not noticeable when the plug is cold but when the plug heats up the electrodes expand and causes a lack of Spark.
It's funny watching this video I just went out and bought a tester this afternoon to test my Spark plugs in my new jet ski that I purchased that is not running and three mechanics have worked on and can't figure out why it wasn't running so I picked it up for 15,000 pesos in the Philippines with a trailer that's worth 25,000 pesos LOL because they couldn't get it running
The motor itself according to the Spark plugs and lack of oil runs properly or did when it shut down so it hasto be a spark issue or electronics issue.
Either way in a short period of time I will have ruled out any breaks in the electronic harness with the tester I purchased this afternoon and from there it can only be power pack which is as you note a sealed unit and must be replaced as a unit as a last resort.
Absolutely ridiculous price of the electronic power pack in a jet ski GSX limited-edition SEA DO,,, $1000 plus shipping but it will be cheap if that corrects the problem considering I just purchased a jet ski worth 4000 American dollars for about $350 with a trailer that's worth more than what I paid for the unit and the trailer itself.
Good upload and I will share it to Facebook.... not that any of the dweebs on my Facebook account would understand what you said LOL
And I subbed your channel
my friend I have been living in the Philippines for five months now and have in a beautiful Apartment with a view of an ocean which is about 50 yards from my apartment and deck which makes my view in Florida look like a Manhattan tenement LOL
I have a white sand beach and Miles beautiful coral right behind the house and I just purchase a jet ski that I am working on in order to travel around the Philippines via the ocean traveling method...
go to my channel then look at all the videos of over 100 I have made of the Philippines is a beautiful place... once you get past the fact that the people are basically not very well educated but are pretty much friendly to the American dollar and to the people and have them so I am enjoying the lifestyle here immensely.
To see where I live you can Google
Wish You Were Here in ALONA BEACH
and thanks for stopping by
Thanks for watching and subscribing!
$1000 for the CDI/power pack.....what a bunch of criminals. I would try and remove all the potting material and swap out some components before I bought one. LOL . I would do a continuity test on every wire from point A to point B. My jet ski had one wire that corroded inside the insulation. Luckily I found it.
electronicsNmore that is precisely why I bought the meter a.k.a. to test each and every individual wire in every part of the harness From A to B.
All it takes is a small crack in the insulation in a little bit of salt water and it will corrode internally as you well know.
Plus if I showed you the video I made of the harness you would see that the three so-called mechanics peeled off some insulation about 3/8 of an inch long and twisted the wires together without cleaning the wire itself prior to twisting it which means it may not have any continuity whatsoever because they twisted oxidized wires together not knowing anything about oxidation because they are not mechanics in the true sense of the word.
I however went out and purchased a nice little wire brush some flux 40/60 solder which is still legal in the Philippines I'm the properly spliced them together laterally like this supposed to be.
Went to 12 stores in the last week looking for some heat shrink... and no one even knows what it is here in the Philippines so I purchased some 1/8 inch diameter clear hose used fish tank filters and after the joints are soldered I will put some black high heat silicone over the wire and slipped the tubing over that which I'm sure will be sufficient to keep it from getting wet...
The machine ran perfectly until it was left unattended for a few months and when the man went to start it again it just didn't start so probably the electronics is not the issue and probably more like one of the three fuses I found that were blown??
Do you think? LOL
We shall see,,, it's the 1494 in. cubic centimeter engine and if you look at it in the video I make this week you will say it looks like it just came out of the factory however when you look at all the cannon plugs you can see that the high-quality brass male and females are completely oxidized.
So I will take my little files and drill bits and polish them up in an out.
Between that and a proper soldering job and testing the wires themselves I should have ignition when I'm done with that.
There are some heat sensors on the top of each head and also in the exhaust loop and I'm not sure if they will shut the motor down what I will check those as well and the tubing that goes to the sensors.
This is my first jet ski and it didn't come with a service manual so I will look online I'm sure it's there but only purchase this machine three days ago and this is not my livelihood is now my hobby which I devote 10 hours a day to anyway LOL
If I have any questions I will be sure to bring them up on one of your pages after I do some research on your videos if it is not covered somewhere that I can find?
If I don't I still believe it is something a lot simpler than the power pack and that is my last resort
and you are right it's highway robbery.
Okay my friend thank you for returning my comment and best wishes to you from one mechanic to another.
Michael
Where do you work at? Pratt & Whitney?
HoodwinkedbyanAngel Michael Fazio I am so glad I came across this video and y’alls ‘troubles’ after acquiring these sea-doos. I myself have been given one and it too was a ‘it ran perfectly when I shut it off but will no longer start’ scenario. 👍👍 I say “perfect!” as it too does not have any spark. Seeing as I love electronic/electrical type work I welcome the challenge...and hey, for the price?(free) I am ahead of the game already if it actually does need a part or two. Any recommendations where I should look first on one of these beasts? I have done two stroke ski-doos of all types so that part is pretty familiar, just not their watercraft. You say the ‘power block’ can/may be an issue?..I’m guessing it’s to do with leaking water internally causing it’s many quirks.
Let me leave y’all with one recommendation when cleaning up corroded wires....you will thank me for this later..trust me. Whenever/where ever you have corroded wires needing to be reconnected and you find ‘sanding’ them or ‘scraping’ them with a blade don’t quite do it, try dipping them in muriatic acid from the hardware store. This product is used for cleaning and etching concrete in pools etc. NOW BE BERY CAREFUL WITH THIS STUFF!!! IT IS HIGHLY CORROSIVE AND EXTREMELY TOXIC!! USE IT WHERE THERE IS EXCELLENT VENTILATION AND KEEP CLEAN CLEAR WATER NEARBY TO NEUTRALIZE IT WHEN DONE. It takes only 10-20 seconds of dunking this in the acid and it’s done..clean. Quickly rinse it off with the clean water and dry it off completely. Do give it a few passes with the emery cloth or sand paper to get that brilliant copper shine back which makes it the easiest to solder. I know the good heat shrink is the best but I see not always available. Check for a product called ‘liquid tape’. It’s black in colour and smells a lot like contact cement. (😮 💡 😮☝️👍...did the lightbulb just come on? 👍😉) ...I believe if there is no liquid tape available, you may be able to improvise with the contact cement...I’ll leave that up to y’all to figure out 💡😉🤞👍 Spread this liberally on and over the newly soldered connection right onto the wire’s insulation so no water/moisture can penetrate it. Cover that with electrical tape to help stop any possible abrasions that may occur.
Thank you kindly for any tips you may have for me and I hope mine will come in handy for you. With any luck it won’t take me long to repair it as up here in northern Canada, our ‘Sea-doo season’ is already awfully short as it is..from October to June the ice makes for some powerfully rough and cold boating on a sea-doo anyway. 😆😆😁😄🤣 All the best from a fellow mech. and watercraft enthusiast. 👋👋👋
In my opinion it's up to u or whoever is performing that task . Most mechanics should know how to test plugs . If u don't have time to test the plug then replace it . Or if don't have money to burn then test it. Do whatever works best for u .
yep the insulater is the bit at the electrode end of the plug, look under the electrodes, if the porcelain goes deep , it is a "hot" plug ie: there is a longer path hor the heat to escape to the metal body, if the central insulator is short and stubby, the heat escape path is short and effective, ie: plug runs 'cooler' ( a old plug) Cool plugs will oil up , hotter plugs will burn it off. ie: a champion n3 has a short insulator and a L7 has a long insulator
Correct. My "Pinned" comment clarified all that.
Thanks! I have an older Ford truck and it's starting to get bad gas mileage, nothing else wrong, I keep up with it really well, clean air filters, the oil changes, anything it's needed gets done. She does have high mileage but it's never sucked gas like this in the 8 years I've had her.
You're Welcome! Be sure to rate "Thumbs Up" and share. Also check out my other videos as well. Could be a loss of compression. Do a compression test. Any smoke in the exhaust? If not, could be dirty valves, or a fuel system problem. Spark plug wires/plugs can also contribute to a loss.
StormieinFlorida You might want to check the lambda sensor if your truck as one (or two). They tend to be forgotten and performance degrades with time.There's enough videos around to give you some insight on how to check it with a multimeter. Good luck ;-)
The type/brand of plug can indeed matter. I (and some friends) have only ever had good luck with NGK "V-power" plugs in our older cars (mostly V-8's). They last longer/run better,in my (our) experience.
Some newer engines can be picky about the brand of plug as well.
(I've even had good success using the NGK's in place of platinum plugs,in some newer engines.)
Hi,
I never stated different types/brands of plugs did not matter, what I did say is the procedure outlined in this video works on all plugs. In my experience, using split fire / bosch platinum / NGK / autolite, I noticed no difference of performance with my personal water craft, cars, mowers, etc. I can probably switch out a plug that someone insists works better(without them knowing), and they would likely notice nothing.
Thanks For Watching!
I see you talk about the resistor in this video as well. The resistor is to stop capacitance after firing of the spark plug. As the ignition system operates, the shielding in the plug wires builds up an electrical capacitance, ( just like a capacitor does). Once this capacitance is so strong, it'll jump the spark plug gap, this isn't good, so they build a resistor into the plug to bleed this stored electrical charge of slowly so that it does not jump the plug gap, and ware out the electrode tip prematurely. It can also lead to pre ignition. The electrically induced noise that you hear over your cars speakers is caused by the alternator frequency change when the capacitor goes bad in the alternator. The capacitor is an electric filter in the alternator, it performs the same job that the capacitor performs in an aircraft magneto p lead, it acts as a filter to filter out electrically induced radio noise. I'm not arguing, I'm just setting the info straight.
Great comment,
wanna chat let me know thanks
Sometime a plug can make a spark on the chassis and not in the cylinder head, its caused by the pressure, its a big factor in plug spark capability, and fooled plug can some time be recovered by burning the tips after cleaning it out with gas
You offer good info for the info you have learned and it is kind of you to share this info with the public. I am searching for remedy for a small engine's ignition deficiencies that brought me to your video. However- please do
let me point out that during this video you explain the "heat range" of spark plugs can be determined by the length of the ceramic insulator that remains outside of the combustion chamber during a plug's operation when in fact the exact opposite is the truth. It is the plug's business end that is within the combustion chamber that has a longer or shorter measure of exposed insulation or not that determines the " heat range" of that plug. A small bit of misinformation may have consequence of temporary or possibly immeasurable value. Such value compounds when the misinformed do indeed spread to others what they believed to be the facts. You have had over 1.6 MILLION views of this video, it is that fact which motivated me to point out one important fact of operation.
The "Heat Range" issue was clarified in the video comment section a long time ago. Read my "Pinned" comment. Thank you!
To locate a bad plug just remove the plug coils one at a time while the engine is running. If the engine idlization doesn't become rougher and stays the same that means that plug is not contributing to the performance. You can try cleaning the plug if it's dirty, regapping and blowing out the socket port in the engine for debri.
Well , I have fully rebuilt a Stihl hedge trimmer due to low compression & fitted a new carby due to having a leaking main nozzle check valve, the ignition coil was also replaced due to having no spark.
The spark plug isn't NGK but their electrode resistance is 5 K ohms for their resistor type spark plugs,the plug I have measures 9 K ohms which I am told is too higher resistance which can cause hard starting & rough running , in my case I have a no start issue meaning that despite the spark plug having spark when removed from the spark plug hole there may not be enough voltage at the electrode to fire the air/fuel mixture in the engine.
While the spark plug ran a Briggs & Stratton 4 stroke lawn mower I noticed the motor was harder to start & didn't run as smooth (surged) at medium to low speed (idle) ,actually it stalled at idle with that spark plug.
NGK suggests a maximum of 5 K ohms from the spark plug terminal to the centre electrode,I am off to the auto parts store tomorrow to see if they can supply me with a suitable spark plug.
Excellent info! Had no idea all these years how to test plugs. Thank you👍
Nothing is 100%, but it does work very well.
i understand some plugs r cheap, but, we had a problem one year going thur champion plugs anywhere from two day to two an hour it was bad, anyway its nice to know how to be able to ck out if a plug is actually done, great video
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Good Evening . Thank you very much for this video. I want to ask you this: all spark plugs - no matter what brand or if they are NGK all types NGK new ones when the readings show the same ohmic resistance? E.G. the NGK (BKR6EQU), (6002) new how much should it read? New I had not measured it but at 54,000 kilometers when I changed them and measured them they show (4.16) k.
Regarding all this, what is your opinion?
Thank you .
You need to refer to the manufacturer's spec sheet.
good info . never heard that before . I was going to comment on removing plugs from a hot engine , but you covered that too . I have 4 plugs I saved I'm going to test .
Thanks for watching!
Very usefull for me......need some further advice on how to rule out a spark plug wire- some say that the lower the resistance the better the plug wire is....Magnecor says different and makes plug wires with very high resistance; so what do you advice me to choose? and of course, before choosing a new plug wire, what should I check to make sure I need to change it?
The resistance has nothing to do with how good the wire is. Wires are made for extremely low resistance, or high resistance. The insulation of the wire is what matters more. I suggest you contact the manufacturer to find out the suggested wire type to use.
Thanks For Watching!
electronicsNmore Got it.....so here are some further questions:
- since insulation is what matters, can I use some extremely good insulated ones like magnecor even though they have higher resistance over standard ones....?
-manufacturer (Renault) doesn't say anything about their types...
-how can I check a plug wire to see if its good or bad?
Likely have no problems with that wire. You can measure resistance across the wire and make sure the ohms per foot matches the manufacturers specs. Place the spark plug wire VERY close to the engine block at night and see if you observe any high voltage discharge(or corona) between the wire and the block. If you do, the insulation of the wire is degraded.
electronicsNmore Got it....instead of placing the plugs wires very close to the engine block- my wires are very short, cant get them close to engine- can I spray some water on them and see if discharges occurs?( using some of those "devices" used to clean windows set on "mist" to spray the water)
ncomplex1 Wires are just one part of the ignition system. Changing the type of wires without further modifications, or the need for them. Will not bring you any particular advantage, other than just spending money.But if your gonna replace it anyway, please make sure its up to at least manufacturer standards. ;-)
Thx for this video. What you are saying from 07:10 made me check and clean my spark plug thoroughly and now my scooter starts no problem! Great video. Thx again
In the past I measured the resistance of the new plug compared to the resistance of the old plug and gave the plugs a tolerance of 20% . That is how electronic resistors are ; with silver standard being 10% and gold standard being 20% . The plugs I use are cheap and when my cars computer starts tripping codes for bad plugs they are usually around 20% .
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If you have insulation tester, that’s better way to test the leak. It has high voltage of 500 or 1000 volts (most usual values, some have 5kV or 10kV) between the leads and measures the insulation resistance usually 500 or higher megaohms. Older models are available quite cheaply if they don’t have moren measuring algoritms. I found one in 30 euro. These are good if you measure HV cables too.
Yes, a megger is great, but most people either don't have one or cannot afford one.
Most people don't know this because you don't need to do this. All you have to do is hold the threaded end against chassis ground to see if it sparks when cranking or running the engine. This will also indicate that power is getting TO the plug. If no spark you can repeat the test with a piece of bolt in the plug wire instead of the plug.
You pointed to the wrong end when you indicated longer insulator means runs hotter. How far and thick it comes up at the spark end determines that.
FYI, spark plugs practically never break apart in the middle, except possibly if you have trouble removing it and damage it doing so. Far more likely would be the tip has eroded away or is fouled too much, which might not be reflected at all in your direct contact meter ohm test.
However this is all fairly silly. Once you've gone to the trouble of removing all the plugs (unless you have a specific cylinder misfire code), you might as well replace them. Spark plugs are not expensive in the grand scheme of vehicle repairs and far more often it's the hassle removing them in modern tight engine bays, not the expense that deters people from replacement, especially if it's a "V" engine instead of inline that has plug access at the top.
As far as people claiming a plug is bad, that is very rare unless the plugs have so many miles on them that the owner already expected that it was time to replace them. I've been on multiple car forums for over a decade and am quite sure that spark plug paranoia is rare, except with specific engines known to, or evidence of excessive oil consumption which is noted by a drop in oil pan level.
Your method is not a sure way to test the plug. I outlined all tests in this video which have been proven to rule out the spark plug as the cause of engine trouble. You must learn to read PINNED comments before posting comments. Lastly, do it your way if you don't like my method. I never force anyone to do anything on this channel.
Some might remove 4 ngk plugs on a motorcycle (which are easier to do depending on the setup) and pay $10 or more to replace them. Thats at least a 6pack ! Y not clean them and reinstall if they are good?
Stinky Cheese. I just replaced 18 spark plugs on a lycomin R 680 radial. Most the plugs had a resistance of 9.68 m ohms, that's 968,000 ohms of resistance, 5,000 is the point of replacement. Huge difference, these plugs still fired at low pressure in the plug spark tester, but when the pressure is increased in the tester to simulate the high cylinder pressures, the plugs stop firing, those are bad plugs. You can test your plugs all you want like you have explained, but it means nothing if they spark. Because there are no cylinder pressures acting on them to reviel that there faulty. That's why an engine alot of time will idle fine, but when you accelerate and open the throttle valve, the pressure in the cylinders increase and the plugs start to miss fire, creating a loss of power. You need your multi meter set to ohms, 1000 to under 5000 ohms is good, and the SPCT spark plug tester to simulate cylinder pressures while sparking the plug. That's how you test plugs. That will reveal bad plugs.
I agree. Been working on vehicles for 35 years and what you're saying is true. Aircraft plugs are worth this test because they cost about $40 each, low end. Thanks for sharing.
HI, good video....I have a question on my champions spark plug UL77V
when I measure the resistor like you did...using an ohm meter Fluke 60M
from the center of the electrode to the center tip the reading for all is over 60M
is this normal reading ? the test was perform on a bench (cold)
Thank you
Mo Mo I do not know that particular meter, but if you are getting results that do not match what I showed in the video, then the plug is likely bad. You should have no reading between the center electrode and metal threaded body of the spark plug using the highest ohms range on your meter. Perform all tests hot and cold to rule out the plug.
Thanks For Watching
Hey good vid ..I once had a issue with a plug that was fine, sparked fine ,but when under compression would not function at all..it just about wrecked me.
Luckily I never had that problem. It doesn't happen too often.
What do you think of spark plug blaster cleaner machines?
This procedure only test for one failure mode. There are several other failure mode. Think of cracks in the insulator.
Never remove a spark plug from a hot engine.
As a rule: when you take a plug out, just screw in a new one.
And do pay attention to the recommended installation procedure:
- use of lubricants (many plugs do not require lubrication)
- way of torquing (depends on seal used)
- use a proper spark plug socket or risk cracking the insulator.
Actually it tests (2) failure modes. An annotation was added which explains how to test the plug heated up to rule out any insulator cracks or heat related issues. Good ole toaster oven set for 300 deg F.
A merger would test insulation.
good vid and info, I am old and have done many types of mechanics my whole life , I wasn't aware of this...thanks for taking the trouble to share friend...God bless...doug
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Many thanks for the presentation. More, and more frequently, resistor plugs are being used in small engines, Does that resistor further increase the spark's voltage across the terminals ?
How do we know what reading for spark plugs should be for year make and model of vehicle? & Also the readings for other electrical parts like ignition module etc?
Hi Ramon. You can look up the spark plug number online for more detailed specs. Thanks for watching! Be sure to rate thumbs up and share my channel with others..
Very good video..Easy to understand for even a novice like me and your explanations are very thorough.
Thank You! Be sure to share, rate "Thumbs Up", and check out my other videos as well.
very good gentleman, I am driving 1000 cc suzuki cultus, four cyclinders, It is 2012 model, EFI. The engine started to miss on CNG and a repairman changed a sensor on carbeurator. but later I started to feel misfire or sometimes light blasts in left cylinder. I removed that plug and put it into right side cyclinder, but then I felt misfires in right side cylinder. I removed it and purchased a new one, however your tutorial was realy very informative, now I will check the removed plug, wether it was out of order, however it was newly installed. There was a loose connection which not only damaged the wire but also damaged the plug.
JACK
Kishan Patel you're an asshat, kishen. I for one enjoyed JACK's story, so there.
great video very informative I've known about the lean rich hot cold what the pulg is telling you about the engine and fuel delivery thanks for taking the time to share your method of testing
Be sure to check out my video playlists and share. Thanks!
What is the range of KΩ you are supposed to get with automotive spark plugs with an internal resistor?
You said roughly 6.3KΩ but I need to know the exact min and max!
With 2 pin COP ignition coils it's:
▪︎ 1.0Ω or less for primary coil
▪︎ 6.0-8.0 KΩ for secondary coil
I would appreciate it if you can tell me the resistance range for a standard copper E3.48 DiamondFire spark plug or any standard 98%Copper with 2%Nickel spark plugs and Platinum or Iridium if there is a difference
Doug, thank you for your concise and informational video. A couple of questions...is it possible to test plug for spark while it is still in? Also, my specific application involves a non-working leaf blower, therfore i cannot test a "hot" plug; does that matter? My guess is that there are lots of people who are testing their plug because it can't "get" hot! Thanks again. dc
Excellent information, I was just wondering when testing the resistance of a lawn mower plug how does a resistance test work on a lawnmower plug that has NO resistor? my understanding is that resistance is load from a device or a restriction of current flow by the use of an actual resistor and a NO resistance reading is ZERO OHMS so you would not be able to get a resistance reading from a NON resistor plug of course so to tell if a lawn mower plug is defective you will just get the ZERO OHMS reading yes? what would the OHMS result be on a defective lawnmower plug then? NOT higher than ZERO I would imagine because there is NO resistor, i'm confused.
+Thetrucky69
If the spark plug has no resistor, then the ohms reading should be very low(zero or close to it). When a mower plug is faulty, it will fail the high resistance(Mohm) test. Also test the plug after it is heated up to 300 deg F in a toaster oven for 5 minutes. Be sure to handle the plug with gloves, and place it on a thick bottom glass (turn the glass upside down)for testing. Do not touch the spark plug probes or spark plug while testing!
+electronicsNmore I am still confused about a faulty lawn mower spark plug failing the high resistance test as a NON resistor plug should ONLY be expected to show a very low OHMS or ZERO OHMS reading anyway but you don't need to reply. I am not trolling mate as I just like to learn but don't want to irritate you. Excellent tutorials mate I am subscribed cheers.
Thetrucky69
The LOW resistance test is between the electrode tip and end of the plug where you attach the wire. For a mower, that is usually a reading very close to zero ohms. The HIGH resistance test is between the end of the plug where you attach the wire and the body that threads into the block.
+electronicsNmore Ok now I get it, I am going to watch your tutorial again and pay closer attention thanks mate cheers.
+electronicsNmore
Hey mate, what happens if I only have the needle multimeter without the red negative clip?
I have heard different values with ohms readings (multimeter) for small engine spark plugs (mower, snow blower, etc.). Can you set it straight for me? Some say a good spark plug should read 500 to 5000 ohms. Others say 4000 to 8000 ohms. And still, others say 5000 to 15000 ohms. Which is it? Or, is there another standard of values to use?
I have a snowmobile that eats plugs like smarties. Sometimes only get a couple minutes out of them. The plugs test good but will not spark. I've even tried them on different machines. The snowmobile is a 3 cyl 2 stroke. It's not the same plug that goes bad either. I'm very confused. This system fires all 3 plugs at the same time with 3 separate coils. Any Idea what would cause a new plug to blow but still test good?
Very good job 👍👍👍👍
Nice video 👌👌👌👌
Very good teaching 👍👍👍👍
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Muy bien ilustrado,teniendo en cuenta que los manufactureros NO recomiendan quitar las bujías hasta que el motor se enfrie pero, entiendo que al hacer las .pruebas en frió al conectarlas otra vez para probarlas calientes, las podría dejar menos apretadas para que no vaya a ajustarse mucho da~ando así la rosca estando el motor caliente y así hacer ambas pruebas, Thank's.
To be for use one would need to know the acceptable resistance of the plug in hand. I dont know what mine is supposed to be. Looking at your tests I could come back with anything from 0 ohms to Kohms on a plug, but unless i know what its resistance IS then i cannot use this test to any effect. Any rules to apply here? Thanks
Nick Hudson Vehicle spark plugs are resistive. Uually in a range between 3500 and 6500 ohms. All you need to do is Google the spark plug you have.
good instruction . I use to clean rifle carbon buildup with vinigar .. don't know if it will work ..?
Hi,Thanks (what's your name?), Nice video. Just a couple of questions...how do I tell if a plug has a resistor or not from the outside? (from looking at it?) and there was text saying don't sand platinum plugs but didn't tell us why? Thnx again, Bj
I'm Doug. You can tell if the plug has a built in resistor by the part number which usually contains an "R" at the end, or you have to use the DMM to test it to find out. Platinum plugs are "self cleaning" plugs. There is a VERY small dot of platinum on the ceramic tip, sanding it will damage the plug. No need to clean those plugs.
Thanks For Watching!
Can we conduct this test for platinum plugs? I was told not to touch the electrode of a platinum plug because they're very sensitive and will likely be damaged.
I don't recommend it. The spot to touch with the probe is so tiny, you'll get a false reading.
@@electronicsNmore Thank you very much for replying. So this test is only good for copper spark plugs?
@@renejacques8288 No, it works with others.
@@electronicsNmore The only one left is iridium, right?
@@renejacques8288 It works with all 3 types, but easily with copper and iridium.
Do you expand on another video that point being able to tell what's wrong with an engine just from checking the tip of plug ?
Too many others made videos about that. Thanks for watching!
Great video, concise and thorough and not boring as some of the educational vids on youtube are, these are important facts that anyone mechanically minded should know and in case they forget its good to come back and have this as a reference. Thanks! Big thumbs up :)
Thank You Greg. Be sure to share my channel/videos with others, and rate Thumbs Up.
Allow the engine to cool down to a room/shop temperature. (most applications). Attempting to remove the spark plugs from a HOT engine may cause the spark plug threads to seize, causing damage to the cylinder head threads. ... Also contaminated threads may prevent the proper seating of the new spark plug.
Should there be any reading if a DMM is placed on one end of the insulator and the other?
Victor Aberdeen If you touch where the electrode is and where the spark plug wire connects, yes.
The DMM is being placed in series with the porcelain.There is no contact to the steel shell or center electrode.That is the question?
What I am enquiring about is where I place one DMM lead on one end of the porcelain and the other lead at the other end of the porcelain.Bear in mind that there is no contact to any metal surface.
is there a way you can show your tester on what settings. I have a tester but don't know if I'm using it right.
Which model tester?
It's a greenlee
_lh3.googleusercontent.com/Oo4hxU5BbFi5hoJrA5MRW5lDIPM0W7vTuoqkm4LxsY5zzSZpD4Os9jsybRWqnb_5vTRqatHh0g_
***** what model...
DM-20
For the 1st test in the video(measuring plug resistor), use the 20K range, lower left, for the second test using NO hands, use the 2000K setting. Just to let you know, that range is not that high. For a reliable test you need a DMM with at least a 10M range.
Is this video valid for iridium spark plugs or have they diferent measures?
+Joaquim Coutinho
They test the same way. The only difference is the electrode is made of Iridium.
+electronicsNmore I have 4 iridium plugs for my yamaha. Cyl 1-2 have a value of 4000 ohms, cyl 3 has a value of 7800 ohms and cyl 4 has a value of 3700. Could that cause some rough running (misfires and loses power) at higher rpms? (The plug with a high value is also black compared to the other ones that look normal. (no oil residue, just black in colour)
The coils check out OK.
Narii- try to clean the iridium plug and measure again the values seeing if anything changes?
***** Swapped them out for new ones, runs as it should now. Need to sync the carbs tho.
TU good info..but if the plug is hot , doesn't that mean the engine was started/running so no point in checking it?.
It was just an extra test to ensure the plug works fine when hot.
Love you clear concise no nonsense delivery and relevant annotations.
Do you only do the cold and hot tests to rule out starting/performance problems that are happening within the maintenance schedule or to also extend the maintenance schedule of spark plugs. Would you then oppose the recommendation of replacing all your spark plugs at the same time? Thanks.
ourlegacy The cold test is usually good enough(At least for me), but to be 100%, you should do the hot test. Replacing one faulty spark plug can make the engine run great again, but usually you would replace all the plugs at the same time.
Thanks For Watching!
Hi can non resistor plugs and plug caps. Hurt the c.d.I. on gy6 scooters?
Oh! My bad !! I do have a NGK BPMR7A spark plug for my hedge trimmer , the Briggs & Stratton lawn mower has the Champion plug which is a non resistor type, I compared the resistance between the Stihls spark plug which is actually 9.53K ohms & my dads Honda leaf blower which has a 10.5 k ohm resistor inside of it & runs good so I need to confirm why the readings for both NGK spark plugs are at around 10 K ohm whereas others I measured which are for a Honda lawnmower & other GM spark plugs (Denso) measure at between 3 - 5 K ohms so I am looking for an explanation for that ,is the BPMR7A spark plug supposed to measure at 9.53 K ohms?
+Russell Booth
Hi there. The actual resistance reading will vary. You can look up information for the type of plug you have online.
Thanks
how about a bosch super 4 i've found a faulty one that says its (connector to tip ) 4.95 ohms resistance, but it also has 980 on diode check, does not spark others that do work are in rang off 5.48 to 5.66 ohms and have a good spark, no shorts to shell on any of them have you come across this before. ?
Your resistance readings are in K ohms, right?
yeah its in K its auto setting multimeter cat3. sorry for delay been bizzy. its the only one of 4 that has a diode reading, changed it for a spare one i have and the engine runs now without missing, but ordered a new set. just dont get how its coming up with a diode reading.
Thank You for those tips. Testing spark plugs before purchase them would save us time, work and money as well.
According to NGK's web site, the heat range is determined by the length of the ceramic in the nose of the plug, not back at the wire connection.
+kr4mo
Hi there. I guess you had annotations turned off. Very bad when watching my videos. :-)
Which one is defective now, as it confused when you get zero reading, but still you said it is ok
From my experience working on bike engines:(1) Does it have NGK written on it??(2) Is it more than 3 months old??(3) Is the plug black??(4) Replace the plug with a better made brand (or just replace with another NGK plug if you enjoy frequent spark plug issues).
+Andy Reid as a fellow powersports mechanic, I run NGK in all my stuff and dont have issues with them
+Zyggiespace I own and work on a lot of 1970's 2 stroke bikes running more than 9:1 compression ratio and have found that NGK plugs don't like (A) high compression ratios and (B) 1970's 2 strokes that tend to "buzz" a bit when on long trips. The faults that is typical is that after 15 to 20 miles of open road high speed riding first the bike starts to cut out occasionally on one cylinder (or starts to judder on a single pot motor) when the throttle is opened up. Then the plug just stops sparking and the rider pulls over and suspects (wrongly) that something like a wire has come loose. After much fiddling and faffing about the fault has apparently cleared itself (the bad NGK plug has cooled down) and the engine starts and runs perfectly..... for the next 15 to 20 miles and the whole thing starts again. If I had a beer for everytime I've had this happen to me or friends over 35 years of riding motorcycles I'd be drunker than an alcoholic trapped in a brewery. I surmise, from testing the plugs before and after they've cooled down with a continuity tester, that the problem is that the metal rod though the porcelane between the electrode and pip on the top of the plug moves and looses electrical contact when the plug overheats. Once cold the plug returns to electrical continuity until overheated once more. Breaking open theprocelane on an NGK plug reveals that they are unconventional in the use of a copper rod rather than the more traditional steel or iron rod (as use in Lodge plugs and others) which might be the cause of the problem in that copper expands differently to steel and iron, causing it to break contact when the plug overheats. 2 stroke also run a lot hotter than 4 stroke motors, which doesn't help.
I do know that the Arctic Cat 1100 turbo comes equipped with NGK MR8AI-9 plugs and those have held up to a substantial amount of boost pressure. That might have been an issue with them heating up and breaking in the past, and using a copper core (I have broken some on accident) but they dont use that anymore, Also, todays four stroke engines produce much more heat than two strokes.
+Zyggiespace My local motorcycle repair shop owner confessed that the reason why NGK is the only brand they carry is because they have a higher turnover than when they stocked Nippon Denso, Champion, etc. and having worked in a motorcycle dealership in the recent past, the same was true with that place too. The repair shop owner said that when he sold somebody a plug they didn't need to replace it for more than a year or even two years. By comparison he can guarentee that a customer will need to replace an NGK plug per cylinder every 4 to 6 months on a everyday use commuter bike. He even spent 2 wasted hours trying to sort out an ignition problem on a customer's bike during a service only to find out that the brand new NGK plug he'd fitted from stores was dead as a Dodo. He reckons that QA has gone downhill over the years with NGK. Here in the UK NGK is the only brand that every motorcycle shop carries (good turnover!!) so try finding ND, Bosch, Brisk, Champion and as for Lodge, by sheer luck after searching the internet due to the high price. (I've had a set of Lodge plugs last through 3 bike engines over 8 years, but for what I paid for them, I'd expect no less).
+Andy Reid back to your previous comment. I'm not sure what ratio you mix the gas/oil in these 1970s two stroke bikes. or if they run an injector pump. but I see a great increase in plug life, regardless of brand, if the oil is leaned out to a certain point. for example. 32:1 leaning it out to 40:1 or even 50:1. while gaining some slight performance
Can we determine wether he spark plug contains a resistor inside or not by its length. For example, if the spark plug is short that means probably it does not contain a resistor inside?
No
Hi, Does it short when the plug get hot ? Thanks
No. The plug heats up and expands, and if there is a cracked center electrode, that could pose a problem.
So if the multimeter checks the plug as ok, it means with 100% that the plug really creates an actual spark? I do not need to check this by starting it unplugged from the piston chamber to visually see the spark? This test is enough?
Extremely reliable, but nothing is 100%.
What temp should i stop at the 500c cleaning temp ?
Using a torch most of my plug drop below 4kohms with denso ik and ngkbrk
Ok
well , the test meter , whikle checking ohms of center electrode, might not tell you about any crack in ceramic, with which centeral electrode is coated. But, when such a plug is installed, the powerfull current might jump through crack, and engine might misfire, or malfunction due to increasing heat.
Like I said many time before in this comment area, I've never had this method fail. You need to read my pinned comment too. :-)
Is it still ok if my sparkplugs with resistor doesn't reach the 6,000 ohms reading and only has more or less between 4,000 - 5,000ohms is it still ok to use? Thanks
Each plug is different. Look online for the specs for your brand of plugs. 4-5k ohm should be OK.
Thanks for this insightful video I am currently having an engine problem i.e. poor idling performance and I am glad to learn about this test. To make a long story short I have replaced the old spark plugs with a new Bosch brand but still experience loss of power. what could the probable cause be ?
Hi,
What you stated is exactly why I uploaded this video. You bought all new plugs that you did not need. Are you located in the USA? Many auto parts stores will allow you free use of their automotive computer code scanner. Using the code scanner will let you know if any problems are detected. If no code scanner is available, or the scanner shows no problems, then it could be many things. Clogged fuel injectors, dirt carb, bad timing, etc.
Thanks For Watching! Be sure to share, and also check out my video playlists.
Thank you Sir
Bad ignition timing seems a good guess ! It all started with sporadic misfiring at low RPM a few days ago. Upon speeding up, everything seemed OK. In the process of unscrewing the old spark plugs, the ceramic insulator shattered and a small bit fell into the engine cylinder (combustion chamber) I suppose this was an awkard mishandling on my own or it might well be that the spark plug was already worn out and cracked under extreme heat stress. We managed to partly retrieve it with a vacuum cleaner. When the engine was restarted, an ominous sound was heard which quickly disappeared after running the engine for 15 minutes at 1500 RPM. I suppose the engine managed to digest (desintegrate) and expell into the exhaust pipe whatever bits were left. Everything was back to normal however after travelling 15 kilometers a severe loss of power was observed. I will keep you updated as things unfold. The computer screening code you are talking about is called here a diagnostic suitcase. The car make is Ford Mondeo... Greetings from France
@@LEBANON707 ceramic powder will act as sand paper...scorred barrel, damaged valve seals, broken rings etc..
Very well done. Easy to listen to and follow. thank youl
Glad you enjoyed it Jim! Be sure to rate thumbs up, subscribe, and look over my extensive video playlists below for many other videos of interest to you. Taking one minute to share a link to my channel with others on social networking sites would be greatly appreciated. Thank you
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I put plugs in my acuara I believe they were E3 the tip screws on and off. Do not know why. However if get plugs like this put lock tite on them. The tips got loose and the code was no help in tracking it down. I should have checked the plugs. But I did not. $100 later from the dealer felt like an idiot. I am sharing so you can be aware of it. Other than that I did not have any problem with the plugs. Thanks for sharing this video learned alot.
Hi.
I now check in my car.
4200-5800 ohm.
All bad,or this normal?
BOSCH R5 spark plugs.
Sounds typical. Look up the specs for your plugs online.
Using a wire brush to clean the electrode and the anode creates a conductive coating that will short the current path. It is fool proof to use a spark plug sandblaster and they do not cost much at Harbor Freight if you have a decent output compressor but if you use a pancake compressor it might not work so well. Wire brushes do not like park plugs.
I have E3 3.40 spark plugs and when testing one I get 5.65 on one of them and the other I get 7.75 on a cold test with the meter set to 20K ohms. Is this normal? I seem to hear a tinging noise on WOT after doing an ignition tuneup.
Sounds like the timing is off. See if using a higher octane fuel stops it.
@@electronicsNmore thank you. Was thinking about that about the fuel. It's very faint sound but it's still noticeable. I will also run the car without the dog house to get a better hear on it. Also I just check the other side of the engine and one of those spark plugs came out to 4.45 ohms If I remember correctly. I have a 351 Windsor V8.
The temperature range is variable by the length of the insulation around the electrode tip to where it connects to the body and not the length of the top of the plug, the shorter the insulation the colder it will run also insulation break down is a common failure, tiny tracts of carbon impregnate the crack and will earth down to where the insulator connects to the plug body.
In the video I stated that a longer plug(longer ceramic insulator) is hotter, which is accurate. The rest you mentioned is accurate as well, which is why the high resistance 20 meg test is used.
Thank For Watching.
electronicsNmore No, I think Mentorcase is right - you were pointing to the UPPER part of the ceramic insulator being longer, he's saying it's specifically the LOWER tip part having a longer exposed part that makes it a hotter plug. This latter part is the where the heat of combustion is concentrated and a longer exposed ceramic tip gets hotter and burns off the carbon better. The length of the upper ceramic part has nothing to do with it since it's above the metal heat sink part of the plug. See www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp for example.
That is true, but the longer or shorter nose, usually corresponds to a longer/shorter insulator as well. :-). At least the plugs I have seen.
Much easier to remove the plug , ground it and check for spark while cranking engine, coil is easy to test and doing it this way can diagnose improper gap issues
I measuring the spark plugs for my 1999 Miata. Three of the spark plugs measures around 5.2k ohms. There's one that measures 7.2k ohms can I conclude that one is bad?
All plugs should be "similar". The more important test is the "High Resistance" test from the center electrode to the metal body. If it passes that test, you're likely OK.
Nice video. Is there any other way of checking spark plug than using a multimeter? I mean high voltage breakdown test?
Usually just using a very high ohm range is fine, but if you had a megger, you can use that as well.
The second spark plugs do not read anything and did you said its fine? I'm confused.
One of the tests you should not get a reading, the high resistance test.
Really good educational video thank you.
Your welcome Scott! Be sure to share my channel with others, and check out my other videos as well.
Thanks
In my opinion: If you have a power gap plug or silicon resistor type your won't get any readings until a large amount of voltage goes through it.
Not all plugs have the same type of resistor or have a straight through conductor.