Yes I was gonna suggest the same, I use that trick on vehicles all the time to find vacuum leaks. I’d spray it around the carb too, could be a crack in the intake boot or anything else, that’s a pretty old bike now.
Since re-jetting didn’t have much effect, I wouldn’t rule out electrical just yet. Just because the spark plug checker shows a plug is ok, that doesn’t mean the other components aren’t breaking down.
@@anthonyjacobs8773 I recently had a loose coil wire its more like a complete loss of power than a backfire then FULL power then no power, backfire etc. I've also had bad flywheel which was very similar to this.
Just fought a similar battle on a 2000 KTM with a Keihin carb. Hours of swapping jets. Long story short, it was the carb. Found an OEM (not Chinese replica) and it instantly solved the problem.
Same with my yz125 2003 the carb was bad it had mukui junk so I bought lectron carb now it runs strong 💪 that an apex head its awesome best thing I did to the bike an new piston numura pistons are really strong 💪 I had wiseco burn up an melted ring mess up my cylinder so I been using numura pistons they are good
Agree 110%.. When you pulled the plug the first time and it was wet, I said pull the pipe and check for oil residue. I have had to clear out a CR 250R pipe by burning it out with a propane torch. It did the trick. Peace
And re pack the silencer!!! Every 20 hours is the spec in most manuals, the packing degrades and gets soaked with oil inhibiting the top end of the power band
If this year still has the exhaust power ports, they might be carboned up and sticking. Definitely worth cleaning those and putting stock jets back in. Check the muffler packing too. I have a 1989 that I bought new. Still runs like a champ. Original everything if you can believe it. I love it!
Yep, agree on both possibilities. I've had the exhaust packing etc fall apart causing partial restriction with similar problems. I would have said the crank seals, but as seen, no signs visible.
@qacomputers3344 Still possible but I think his jetting would have made a difference (hidden the problem)... maybe...maybe not. Tough one. Clean the exhaust port power valves. It won't hurt and it might fix the issue.
I REALLY like that bike... I can see why the previous owner was frustrated with it. Like you, I would have started with the carb, but after seeing the air screw only turned out 1/4 turn and inspecting the carb, I would have checked the power valve. I would certainly check it before resorting to completely tearing down the engine because it has decent compression and visually everything looks good.
Just wanted to say that I love the videos Joe. I am 15 and have always had a passion for working on these machines. I have 2018 Suzuki drz 125l and I enjoy upgrading it. Ive been consistent watching for a few years and have picked up on quite a few things🤙
Never cared for the "95" purple. I had a new 94, which was gorgeous. Either way, this was a nice score on your behalf.👍🏼 With some patience, this bike will return a hefty sum at some point. Detail the hell out of it and keep it in the showroom condition that it is.
Joe you finally bought a bike that stumped. You will never accept defeat. All your viewers know that. So I'm looking forward to your next video. I'm curious on what the bike needs to be done to correct the issue.
Check the power valves for sure, they need regular cleaning anyways. But my money is on a bad coil, it's breaking down at high rpm. If it had an air leak from that JB weld or flywheel side crank seal you'd think smaller main jet would make it worse. Looking forward to seeing the fix! Retired auto mechanic here but recently got into small engine stuff and enjoying the change!
Read through all these video comments. Lots of great information. Here is another one, "Before you tear anything down, check the power valve. That's what it sounds like to me"
I know its not the crack seal. The bike would rev all over the place like high low tick overs takes ages for revs to drop down. Power valve or stator or coil, even a bad cdi
Do a leak down test first and while doing so spray soapy water around the jb weld case repair. Check power valve for excessive carbon build up or possibly worn or broken power valve. Silencer may need cleaned and re packed. Clean up all ground contact points on the frame. Had a bike years ago with a bad port job done by a goon that acted just like this. Rule out the above mentioned before tearing it down. Good Luck! It’s a good looking bike!
@jakeowens1770 depends how bad it's leaking and he only tried one larger jet It's nothing to go to the hardware store and fab up a leak tester. Fresh rebuild should have it done every time. He's never done one in his life. It's necessary. You can't rule out something you haven't even checked. But I agree something could be going wrong in the power valves too. Might have to check lol
I'd go with the power valve first only because I had this same exact issue with my '90 YZ 125. Turned out the mechanic reassembled the bike with the power valve backward. After fixing the issue, it was business as usual, with the bike revving out with zero hindrance.
Leak down test… that will narrow it down quickly. All the carb adjusting in the world won’t fix the issue if there’s an air leak. Good luck and keep up the great work and content.
Check the power valve see if the last owner played with the settings in the power valve. You can adjust it to open sooner or later on the cylinder there is a stamp that says H and L check to see the position.
Its really easy to check power valve operation too. Just remove the round cover on the left side and Rev the engine. The line on the end of the power valve shaft should move about 90* from low to high if I recall.
Hey Joe, I've seen something for sale online that removes dents in expansion chambers. It employs hydraulic pressure. It has a pump, with uses water, not oil or hydraulic fluid and comes with caps to fit different pipes. Something that might be of use to you, since you work on so many 2 strokes.
When the jetting wasn't having much effect I was back to thinking ignition. Maybe check the gaps in the magneto pickups, the magnets in the flywheel, coil resistance, ignition module, etc. I could see one of those having an RPM dependent failure, such that it works fine below a certain RPM but then breaks up at higher.
I do believe that dog spends his time stuck in kennel sad if u ask me, mine would of just hoped out the truck after we got home with the new toy, joe rarely includes Vinny…..
What a beautiful bike.. watch all your videos,well most of them. You have fixed so many bikes. I have learned a lot from u. You have probably been asked this a lot but do you keep most of them after you fix them and also have you came across a 85 Honda 250r ATC. Or one of my other favorites 200x. Keep doing your thing bro . Your videos are what I end my day with. Thank you
Joe just did a complete restoration on my 93 CR 250 the kehin pj carbs sometimes just go bad idk what it is did it to me on my 90 CR 125 aswell. Seeing the you can’t get a genuine kehin airstriker right now anywhere the best option for not spending a ton of money on a lectron or smart carb is order a Q&A carb for your bike from Rocky Mountain with a jd jetting kit for a air striker run the needle and main jet from the kit with the needle on the 4th spot down and a 60 pilot jet which doesn’t come in the kit the bike will run perfect. Literally took me a week to figure this out seeing that it wasn’t a genuine airstriker carb talked to a few RUclipsrs about this and the pointed me in the same direction hope this helps in total your looking at about 130 bucks for the kit and carb.
2 stroke dirtbike go-to checklist for me when it comes to performance issues. *Jetting/Spark Plug *Reeds *Powervalve issue/dirty *Crank Seals -stator side will cause air to be. sucked in, causing lean condition. -clutch side will suck trans fluid into crank cavity making bike run very rich Usually one of these is always the cause, of a consistent performance issue. If it's intermittent, especially once warmed up, usually electrical. I see you touched these basis and took all the right steps.
Yeah check build-up in the expansion chamber....and look over the power valves. I'm thinking you'll find the answer in the power valves. Crank seals can def. effect tuning also though?
95 with a stock silencer, check if it has the stock rivits still. May never have been repacked. Revs good in neutral but as soon as you load it up and put more flow i.e exhaust, its no good. Easy to cross this off the check list anyways. Love your work bro, keep it up.
whats the diffrent between 250 - and 450 topspeed ? Iam 186 cm 150 kg and i didnt no is 250 enough power for my weight the bike is for fun and speeding and a bit enduro
Fought almost the same battle same bike. Needle was wore out, new one helped but emulsion tube(part of the body on the pwk) was smoked too. You could never get the jetting dialed. Always sounded like ignition was breaking up or it was going to foul a plug (never did). Swapped parts onto a extra carb body and it was golden.
I think it sounds more like electrical. I had a CDI go bad once that was doing the same thing. I doubt it would be the seals do to the idle is just fine and it's not burning motor oil. Of course it could be just a simple plugged pipe.
I would check the idle jet (the brass thing the needle moves through), since you are changing jetting and reacts in a weird way, I believe it is still related to jetting but most things you already checked. I once forgot to put it back in and had some similar issues.
Another great video, you have more patients than me. I agree with checking exhaust and silencer. Also, you checked the needle jet but didn't check to see if it was the right one. One complaint you do a walked around every time when the unit is in the back of the truck then do another one on the ground, cut one out and will not have to skip forward to you when you are working on it in garage.
First thought when you pulled it off was the crank seals, they get hard and brittle after 20 years on a 2T. All that junk around the flywheel made me think it was blowing premix out on that side. I didn’t see any oil coming out the muffler so I don’t think it is the rhs seal. I guess it could be the power valve not opening.
I'm going with the power valve. Seen it before on the Honda. Also had a similar issue with a Cat snowmobile. Pretty much similar symptoms. Both were dirty/sticking power valves.
Im thinking the problem is with the spark. I would take a look at the flywheel and the ignition coil. Also check the ground of the cdi like you mentioned...
This has me puzzled! You were in the gas coming towards us and a few times it sounded so incredible. I’m thinking the ignition is now not keeping up, maybe the stator or a rubber boot intake with fine cracks maybe
I've had this same exact problem with my 1990 Yamaha YZ 125. Turns out the mechanic put the power valve in backward. Once he fixed the issue, it revved out perfectly again.
I have a 96 250 I have 178 main 55 pilot clip 3 from top air screw at quarter turns out runs great. I also have a 91 125 which had a similar bog as your bike tested everything changed stator cdi exhaust system crank seals and put a new pwk carb on her still had bog. Only thing left to change was coil and ht cap I changed them the bog was gone. Love your channel man hope this helps 🛵💨
I just bought a 03 cr250 with bad bog! It ended up being the power valves were adjusted wrong. the servo motor wasnt opening the ports for mine at the right time. If this ytear has that motor, definitely worth checking! It still has the slightest bog at low rpm so i will be doing a carb tuning like this in the near future. great video, hope you find the cause on this bike, these things EAT!
My 89 CR250 had a very similar issue and it was the power valves not working correctly. The power valves are a different setup on this but it's worth looking into.
my money is on crank seals (due to smoke on first start) or CDI/spark related. It is like the issue i get with water on spark boot/coil grounding out the spark an or if the old cr has power valves being stuck closed.
Any time you got a problem with a bike bogging down or not idling.Or just running rough or something.Always check your crank seals and then check.You can take some break cleaner and spray around the gasket.That seals the crank case up.Make sure it's not weak in there when it's running.If you spray some brake cleaner around there when it's running , it'll rev up if it's leaking. The best way to check it is a pressure test or a vacuum test. What you do.As you plug out the exhaust port, you plug up the intake port.You put a pressure gauge in a trader valve on the intake and you pump some air pressure.You know, 8 pounds or so of air pressure in there and it should hold it for a few minutes.If it don't you got a bad crankcase gasket or a bad crank seal or a leaking gasket around the reed valve or intake boot. You can find the leak quite easily with some soapy water. The soapy water will bubble up right where the leak is... And that right there pretty much covers.Most reasons why bikes don't run good.The only other reason would be the plugged up.Carburetor you know, the jets plugged up or something.Or maybe you got bad gas in it or a bad breed valve or hell.You might have a hole in the piston.Who knows?may even be just a worn out jug in need of a thorough rebuild. By all means, get the cylinder replayed if it needs it.Don't just slap a piston in a bad cylinder.You're throwing your money down the drain?That way save up the money and get the cylinder fixed. I wish I could replate cylinders myself.I could make a fortune.I'm imagining it takes a lot of specialized equipment to get into that though. You would definitely need a good press.Probably a good boring bar.Probably a good home. In a bridge port mill. And the good laid, so you can true up cylinders.Yeah it's still under you know it's down at the bottom. Can't just put the bottom of the cylinder on square and flat granite stone and sandpaper. That don't work because the cylinder sticks down below the mating surface where the cylinder mates to the casing have to put it IND. Send it up and lay it and then clean it up that where you can do it. Unlike a Bridgeport mill. I imagine.
Since the bog is at the mid to upper RPM's only, It would likely be an obstruction in air flow. Check Power valves to make sure they are fully opening at the higher RPM. Also, make sure your pipe and muffler are clear.
I have Lernt sooo much from watching you over the past few years Joe! you have solved Almost Every problem there is. Thankyou :) - Could your problem have somthing todo with the Pipe?/Chamber clogged?
Bogging. Hmm. I remember bogging on another bike, but I don't remember what was wrong. It is always interesting to go through the process of finding out what is wrong with the bike and fixing it. 🙂👍
Thanks for the video could there be a hairline crack in the carburetor making it suck air I don't know I've had that experience on a completely different machine but I don't know it's weird have a better day
yep, the same thing when I repair cast water lines,, drill a hole on each side of the crack, tap the pipe till the crack reaches the holes, then clamp it...
Its not the jetting. Could be bad cdi,Coil, stator, yes or power valve not opening. Its not crank seal. It would rev up n down very weird. Like revs stay high for long like running lean. My guess is stator as ive had this same problem and it fixed it. Also i tested the stator on multi meter and it was fine. Shop told me to replace it and promised me it would solve it. Well obviously it worked. Oh yeh ktm still suffering with this problem. That jb weld needs looking at tho. Im not convinced there is air sucking in by listening to the engine tho
Not for this occasion, but for hard starting,and especially big bores, tilt the bike on it's side until you see gas overflow, put the bike in gear and rock it back and forth. Fuel is sucked into the engine and really helps promote firing. 2 strokes only, unless you want cam chain and valve timing problems. As a long term CR500 Honda owner and rider in all weather conditions, this really saves your right leg and all of it's components.
Vinny just called me and said...David please tell my owner...I am 1000% sure it is the ignition...CDI...coil...I don't want to be near the backfires..😊
Lol! I once worked on a bike a whole afternoon before I realized it had a sidestand switch preventing it from starting. I had the carbs off, plugs out, battery charging and all.
My bet is you will find the slide needle and the emulsion tube are worn where they vibrate around while the engine is running at mid to top end . I have found this many times over the past 50 years most recently on a IT490 K which I junked the carb and put a new carb on it and it was great .
Sounds like it’s never getting into the power band. I’d check the power valve. I assembled a power valve incorrectly in a KDX once and had a similar issue. Good luck!
Yea that sucks i had same problem yz125 2003 i changed all crank seals an i finally bought lectron carb an its fix it junk ass mukui carbs suck i love lectron carbs an apex head @@MrKawie1001
I thought it was rich but it wasn't but I also first thought PV at the first of the video, real fighter here. Been watching you're vid's forever and watched you turn into a top Tech!!!!!!
Check the spark plug cap. Honda uses a resistor cap 5 ohms max. If ohms is 10 or higher with cause a retarder ignition. Also could be stator one coil runs the high revs after 5k rpms . In my opinion it's a timing issue. Cap is a issue I have come across many times. I am 58 years old. Been riding and wrenching for 50 years...
Bog can be lean, rich, bad reeds, burning other fluids or bad ignition. Idle down sounded lean, but it runs worse when fatting the mains?🤔And better when thinning? Sounds like a lean idle circuit but a rich main. An air leak would be helped by fatting the jets not thinning so I don't think you have an air leak but you need to do a leak down test to confirm. Leak down tests are a MUST! The needle clip is stock at second from top but is it the correct needle? Plugs looked rich but not too rich but they were way too wet. I think you have an ignition problem or the carb itself is faulty. I had one on my Yamaha TZR 250 that ended up being the flywheel/rotor. EDIIT: Check the exhaust pipe for fuel. If you have fuel in the pipe your ignition system is the problem. Its not firing as often as it should and fuel is getting thrown out the exhaust port. Also yes the PV could be the problem too. Check that the pully was not put in backwards. Its common with the Yamaha RZ350.
I once had a Yamaha 200 2 stroke 2 cylinder, as a boy of 14/15 year old, and at one point you had a mechanism on the ignition system with, when the engine made more rpm, the spark was made earlier by adjusting the moment that the points were opening. The ignition time was changing with more or less RPM. Now did I buy a complete little set and I just put it on, and the engine did run but did not have the higher rpm anymore. Same as with your bike. I also changed the carburetor, the exhaust pipes, and so on. He had more rpm when I made it leaner, but no power on the top.... I sold the thing before I found that. Then I got a Yamaha YZ250 from I think from around 1985, and there I got the same problem when I got trouble with the engine. The top of that Ignition changer was put on exactly the wrong way, so the ignition time didn't change but stayed the same all time. Again bought it in original parts of Yamaha and I think the did the same thing again: assembled it exactly wrong. I took the top of and turned it 180, so the time changed by more RPM and the problem was gone. It is a bit silly explained, but I am dutch and not very well know with the technical terms in English. I think it is about timing...
spray starting fluid where the JB weld is while holding the throttle at a steady RPM and see if it revs higher due to a leak and sucking air...
Yes I was gonna suggest the same, I use that trick on vehicles all the time to find vacuum leaks. I’d spray it around the carb too, could be a crack in the intake boot or anything else, that’s a pretty old bike now.
Great idea and quite honestly is a pretty easy fix to depending. A good TIG welder can button it up quick if it's not terrible
The intake doesn't suck air from the crankcase, Mr Mechanic.
@@tuberNunya youre trolling, a bad seal, or small crack in the case would cause a vacuum leak
If it was sucking in air then fatting the jets would have helped. He went all the way down to 130 and still same problem.
Since re-jetting didn’t have much effect, I wouldn’t rule out electrical just yet. Just because the spark plug checker shows a plug is ok, that doesn’t mean the other components aren’t breaking down.
Excatly what I was thinking. Does that look like a tape job coming from the stator wire?
Cracked stator plate, throws it out of time at higher rpm, figured this out on a banshee, only after countless hours fukin with dual carbs....
I'm thinking the flywheel has gone bad. He needs to check if there is fuel in the exhaust. If so the ignition system is faulty.
@@anthonyjacobs8773 I recently had a loose coil wire its more like a complete loss of power than a backfire then FULL power then no power, backfire etc. I've also had bad flywheel which was very similar to this.
You beat me to another bike, had this one saved on Market Place myself and was pondering about purchasing. Awesome find and enjoy the videos.
Before you tear anything down, check the power valve. That's what it sounds like to me.
first thing i thought
thats what i was thinkingtoo
Same!
Yep, gotta be the ol’ power valve. Free her up. (I have no idea, just agreeing)
I was thinking the same thing
Just fought a similar battle on a 2000 KTM with a Keihin carb. Hours of swapping jets. Long story short, it was the carb. Found an OEM (not Chinese replica) and it instantly solved the problem.
lol thats what you get for playing with chineseium
@@Skis878 Kei hin carbs from that era are 100% japanese tho
Same with my yz125 2003 the carb was bad it had mukui junk so I bought lectron carb now it runs strong 💪 that an apex head its awesome best thing I did to the bike an new piston numura pistons are really strong 💪 I had wiseco burn up an melted ring mess up my cylinder so I been using numura pistons they are good
Chinese 1s no good then brother?😬🤔😫😫👎👎👎🤝
Do a pressure / vacuum test to test the crank seals .
check pipe , to make sure there is no obstruction ! I had this issue with a 2001 cr250
Could bent places in pipe have caused an airflow restriction? Spark arrestor plugged?
@@DavidPhelps-du1mxdepends on where on the pipe its located
Agree 110%.. When you pulled the plug the first time and it was wet, I said pull the pipe and check for oil residue. I have had to clear out a CR 250R pipe by burning it out with a propane torch. It did the trick. Peace
And re pack the silencer!!! Every 20 hours is the spec in most manuals, the packing degrades and gets soaked with oil inhibiting the top end of the power band
@@Yz4Life fax
If this year still has the exhaust power ports, they might be carboned up and sticking. Definitely worth cleaning those and putting stock jets back in. Check the muffler packing too. I have a 1989 that I bought new. Still runs like a champ. Original everything if you can believe it. I love it!
Yep, agree on both possibilities. I've had the exhaust packing etc fall apart causing partial restriction with similar problems.
I would have said the crank seals, but as seen, no signs visible.
that's a good recommendation, I didn't think of that one,,, a good call,, but I still think its sucking air through the JB weld....hmmm?
@qacomputers3344 Still possible but I think his jetting would have made a difference (hidden the problem)... maybe...maybe not. Tough one. Clean the exhaust port power valves. It won't hurt and it might fix the issue.
@@poorsob
I REALLY like that bike... I can see why the previous owner was frustrated with it.
Like you, I would have started with the carb, but after seeing the air screw only turned
out 1/4 turn and inspecting the carb, I would have checked the power valve.
I would certainly check it before resorting to completely tearing down the engine because
it has decent compression and visually everything looks good.
cleaning and checking the power valve should have been done right along side cleaning the carb.
Ol' Joe loves his dirt bikes. Nice looking cycle, a very popular/big seller, now let's tear it apart. Lots of teaching/learning moments
Just wanted to say that I love the videos Joe. I am 15 and have always had a passion for working on these machines. I have 2018 Suzuki drz 125l and I enjoy upgrading it. Ive been consistent watching for a few years and have picked up on quite a few things🤙
Mid range bog=power valve sticking or misadjusted. Set the power valves up right and try a 170-175 jet. You should solve it that way.
Never cared for the "95" purple. I had a new 94, which was gorgeous. Either way, this was a nice score on your behalf.👍🏼
With some patience, this bike will return a hefty sum at some point. Detail the hell out of it and keep it in the showroom
condition that it is.
I never understood the purple at all??
Joe you finally bought a bike that stumped. You will never accept defeat. All your viewers know that. So I'm looking forward to your next video. I'm curious on what the bike needs to be done to correct the issue.
video coming soon!
Check the power valves for sure, they need regular cleaning anyways. But my money is on a bad coil, it's breaking down at high rpm. If it had an air leak from that JB weld or flywheel side crank seal you'd think smaller main jet would make it worse. Looking forward to seeing the fix! Retired auto mechanic here but recently got into small engine stuff and enjoying the change!
Man i'm stoked you're making this video. I have a 97 that has a similar problem. I replaced the right side crank seal with no improvement.
Just saw this comment a couple of lines below yours, "My buddy's yz 250 sounded like that, and to find out it was a partially clogged silencer"
Read through all these video comments. Lots of great information. Here is another one, "Before you tear anything down, check the power valve. That's what it sounds like to me"
I know its not the crack seal. The bike would rev all over the place like high low tick overs takes ages for revs to drop down. Power valve or stator or coil, even a bad cdi
Do a leak down test first and while doing so spray soapy water around the jb weld case repair. Check power valve for excessive carbon build up or possibly worn or broken power valve. Silencer may need cleaned and re packed. Clean up all ground contact points on the frame. Had a bike years ago with a bad port job done by a goon that acted just like this. Rule out the above mentioned before tearing it down. Good Luck! It’s a good looking bike!
I've said that many times. It's critical to leak test 2 strokes. He's not once done one on video. Never
Word up on the power valves. Had that same problem. Don't think its vacuum case issue as the plug would be white
@@jakeowens1770 he has no idea what the plug is actually reading he didn't do a plug chop
@staygold902 if it had vacuum leak, it would run better with more fuel and higher main jet.
@jakeowens1770 depends how bad it's leaking and he only tried one larger jet It's nothing to go to the hardware store and fab up a leak tester. Fresh rebuild should have it done every time. He's never done one in his life. It's necessary. You can't rule out something you haven't even checked. But I agree something could be going wrong in the power valves too. Might have to check lol
Do a crankcase leak down test, check power valves and check for exhaust restriction.
You know what's up! 👍
Agreed and if all else fails, try a new CDI black box
Take your pick of which to tackle first:
1. Crank seal
2. Power valve
3. JB weld
I'd go with the power valve first only because I had this same exact issue with my '90 YZ 125. Turned out the mechanic reassembled the bike with the power valve backward. After fixing the issue, it was business as usual, with the bike revving out with zero hindrance.
3 first 2 second tear down 3rd
Could definitely be a sticking power valve or air leak.
Leak down test… that will narrow it down quickly. All the carb adjusting in the world won’t fix the issue if there’s an air leak. Good luck and keep up the great work and content.
definitely a crank seal i think, my 250r did the same thing.
Check the power valve see if the last owner played with the settings in the power valve. You can adjust it to open sooner or later on the cylinder there is a stamp that says H and L check to see the position.
Its really easy to check power valve operation too. Just remove the round cover on the left side and Rev the engine. The line on the end of the power valve shaft should move about 90* from low to high if I recall.
I would like to say the powervalve might be gummed up or not opening right. Great Vid!!!
This channel is like meditation for men!
Damn rite ay brother
F yeahhhhh with a Coors in each hand! Therapy !
brother!!
Need to light those 2 stroke scented candles to really feel the vibe!
Weird,
Hey Joe, I've seen something for sale online that removes dents in expansion chambers. It employs hydraulic pressure. It has a pump, with uses water, not oil or hydraulic fluid and comes with caps to fit different pipes. Something that might be of use to you, since you work on so many 2 strokes.
My buddy's yz 250 sounded like that, and to find out it was a partially clogged silencer.
When the jetting wasn't having much effect I was back to thinking ignition. Maybe check the gaps in the magneto pickups, the magnets in the flywheel, coil resistance, ignition module, etc. I could see one of those having an RPM dependent failure, such that it works fine below a certain RPM but then breaks up at higher.
A walk around with our Vinny is just not right 😂
I do believe that dog spends his time stuck in kennel sad if u ask me, mine would of just hoped out the truck after we got home with the new toy, joe rarely includes Vinny…..
Power valve?
@@fordfan6474 We miss the Vinster!
@@fordfan6474I think Vinny may have gotten paddled and is on restriction 😅😂
Power valves or clocked exhaust
What a beautiful bike.. watch all your videos,well most of them. You have fixed so many bikes. I have learned a lot from u. You have probably been asked this a lot but do you keep most of them after you fix them and also have you came across a 85 Honda 250r ATC. Or one of my other favorites 200x. Keep doing your thing bro . Your videos are what I end my day with. Thank you
This was one of my all time favourite bikes I've owned.
It’s favorite 😊 this word is commonly misspelled
@@countrygaming8367 Both grammatically correct... just like color and colour.🙃
@@gableroux136 u took down countrygaming 😘
@@GoatedASF2K That's a victory in my book!
Joe just did a complete restoration on my 93 CR 250 the kehin pj carbs sometimes just go bad idk what it is did it to me on my 90 CR 125 aswell. Seeing the you can’t get a genuine kehin airstriker right now anywhere the best option for not spending a ton of money on a lectron or smart carb is order a Q&A carb for your bike from Rocky Mountain with a jd jetting kit for a air striker run the needle and main jet from the kit with the needle on the 4th spot down and a 60 pilot jet which doesn’t come in the kit the bike will run perfect. Literally took me a week to figure this out seeing that it wasn’t a genuine airstriker carb talked to a few RUclipsrs about this and the pointed me in the same direction hope this helps in total your looking at about 130 bucks for the kit and carb.
Check you harness grounds , ohm out your coil ..even cleaning your fly wheel an make sure it set right , I think its electrical
I will check
2 stroke dirtbike go-to checklist for me when it comes to performance issues.
*Jetting/Spark Plug
*Reeds
*Powervalve issue/dirty
*Crank Seals
-stator side will cause air to be. sucked in, causing lean condition.
-clutch side will suck trans fluid into crank cavity making bike run very rich
Usually one of these is always the cause, of a consistent performance issue. If it's intermittent, especially once warmed up, usually electrical. I see you touched these basis and took all the right steps.
Brilliant video Joe watching from Edinburgh Scotland UK 🇬🇧
Yeah check build-up in the expansion chamber....and look over the power valves. I'm thinking you'll find the answer in the power valves. Crank seals can def. effect tuning also though?
IMO it's pulling air from the crank seals. I would inspect the case for cracks because of J.B weld deal. Joe sweet bike overall 🎬🔥👍🫡
Learned about that issue from Jennies Garage
@@idahoduckhunter Big fan of Jennies garage myself 😎👍.
95 with a stock silencer, check if it has the stock rivits still. May never have been repacked. Revs good in neutral but as soon as you load it up and put more flow i.e exhaust, its no good. Easy to cross this off the check list anyways. Love your work bro, keep it up.
Pro circuit pipes work amazing on these bikes, I raced cr250’s from 1990 to 2008 the I switched to Yamaha 450’s
whats the diffrent between 250 - and 450 topspeed ?
Iam
186 cm
150 kg
and i didnt no is 250 enough power for my weight
the bike is for fun and speeding and a bit enduro
Fought almost the same battle same bike. Needle was wore out, new one helped but emulsion tube(part of the body on the pwk) was smoked too. You could never get the jetting dialed. Always sounded like ignition was breaking up or it was going to foul a plug (never did). Swapped parts onto a extra carb body and it was golden.
I'm amazed at how many times you miss 2nd 😊
Every single time. It's like a trademark.
I think it sounds more like electrical. I had a CDI go bad once that was doing the same thing. I doubt it would be the seals do to the idle is just fine and it's not burning motor oil. Of course it could be just a simple plugged pipe.
Those spark checker can be a simple check but they have no combustion chamber pressure on them so don't rely on it completely or it can bite you
I would check the idle jet (the brass thing the needle moves through), since you are changing jetting and reacts in a weird way, I believe it is still related to jetting but most things you already checked. I once forgot to put it back in and had some similar issues.
I had a 93 same exact bike alot of good times on that machine!!
Very nice bike. As for the issue noticed there's some pretty good suggestions already posted. Looking forward to seeing the outcome.
I reckon power valve sticking as its bogged hard at the beginning. I've had that happen to two yz 125's. If not could be the JB weld, or crank seals.
Another great video, you have more patients than me. I agree with checking
exhaust and silencer. Also, you checked the needle jet but didn't check to see if it was the right one.
One complaint you do a walked around every time when the unit is in the back of the truck then do another one on the ground, cut one out and will not have to skip forward to you when you are working on it in garage.
First thought when you pulled it off was the crank seals, they get hard and brittle after 20 years on a 2T. All that junk around the flywheel made me think it was blowing premix out on that side. I didn’t see any oil coming out the muffler so I don’t think it is the rhs seal. I guess it could be the power valve not opening.
I'm going with the power valve. Seen it before on the Honda. Also had a similar issue with a Cat snowmobile. Pretty much similar symptoms. Both were dirty/sticking power valves.
My favorite Cr250 eva had a huge picture on my wall when i was a lad best look Cr in my opinion lovly nice score mate
Im thinking the problem is with the spark. I would take a look at the flywheel and the ignition coil. Also check the ground of the cdi like you mentioned...
My 2002 did the same thing it was Servo for my ev power valve.
I would check that JB weld repair first see if air is leaking from engine
This has me puzzled! You were in the gas coming towards us and a few times it sounded so incredible. I’m thinking the ignition is now not keeping up, maybe the stator or a rubber boot intake with fine cracks maybe
I've had this same exact problem with my 1990 Yamaha YZ 125. Turns out the mechanic put the power valve in backward. Once he fixed the issue, it revved out perfectly again.
Mechanic)???? Lol
@michaelesposito6678 He was actually a great mechanic. If you don't make a mistake every now and then, you're not doing enough.
Good find.
@@stkyfngrszmooth as long as he fixed it that's great
Did you check that ground where the frame was painted
My thoughts is an air leak from the airbox boot or carb to engine boot.
Maybe just swap the carb out
Looking forward to the next vid and the solution
Check the powervalve. The fact that 155 ran the best might indicate that that the jetblock gasket might be broken.
I have a 96 250 I have 178 main 55 pilot clip 3 from top air screw at quarter turns out runs great.
I also have a 91 125 which had a similar bog as your bike tested everything changed stator cdi exhaust system crank seals and put a new pwk carb on her still had bog. Only thing left to change was coil and ht cap I changed them the bog was gone.
Love your channel man hope this helps 🛵💨
I've dealt with that I'm in outboard business see it alot above 1/2 loses or weakens spark
I just bought a 03 cr250 with bad bog! It ended up being the power valves were adjusted wrong. the servo motor wasnt opening the ports for mine at the right time. If this ytear has that motor, definitely worth checking! It still has the slightest bog at low rpm so i will be doing a carb tuning like this in the near future. great video, hope you find the cause on this bike, these things EAT!
My 89 CR250 had a very similar issue and it was the power valves not working correctly. The power valves are a different setup on this but it's worth looking into.
Love my 89CR250R great bike
my money is on crank seals (due to smoke on first start) or CDI/spark related. It is like the issue i get with water on spark boot/coil grounding out the spark an or if the old cr has power valves being stuck closed.
Power valves, Joe... clean and adjust!!! Could also be a bad spring on the valves.
Then go back to the stock jetting.
Love your show man beautiful Honda keeping ripping
Any time you got a problem with a bike bogging down or not idling.Or just running rough or something.Always check your crank seals and then check.You can take some break cleaner and spray around the gasket.That seals the crank case up.Make sure it's not weak in there when it's running.If you spray some brake cleaner around there when it's running , it'll rev up if it's leaking. The best way to check it is a pressure test or a vacuum test. What you do.As you plug out the exhaust port, you plug up the intake port.You put a pressure gauge in a trader valve on the intake and you pump some air pressure.You know, 8 pounds or so of air pressure in there and it should hold it for a few minutes.If it don't you got a bad crankcase gasket or a bad crank seal or a leaking gasket around the reed valve or intake boot. You can find the leak quite easily with some soapy water. The soapy water will bubble up right where the leak is... And that right there pretty much covers.Most reasons why bikes don't run good.The only other reason would be the plugged up.Carburetor you know, the jets plugged up or something.Or maybe you got bad gas in it or a bad breed valve or hell.You might have a hole in the piston.Who knows?may even be just a worn out jug in need of a thorough rebuild. By all means, get the cylinder replayed if it needs it.Don't just slap a piston in a bad cylinder.You're throwing your money down the drain?That way save up the money and get the cylinder fixed. I wish I could replate cylinders myself.I could make a fortune.I'm imagining it takes a lot of specialized equipment to get into that though. You would definitely need a good press.Probably a good boring bar.Probably a good home.
In a bridge port mill. And the good laid, so you can true up cylinders.Yeah it's still under you know it's down at the bottom. Can't just put the bottom of the cylinder on square and flat granite stone and sandpaper. That don't work because the cylinder sticks down below the mating surface where the cylinder mates to the casing have to put it IND. Send it up and lay it and then clean it up that where you can do it. Unlike a Bridgeport mill. I imagine.
JB Weld on cranckcase is letting in air.
The higher the revs, the more it sucks in, the more lean the mix :)
That’s what I thought, JB weld is a clue for sure
Ding Ding Ding - I think that is the right answer
I agree with some other posters, check exhaust for an obstruction before a teardown. Never hurts to check it.
Since the bog is at the mid to upper RPM's only, It would likely be an obstruction in air flow. Check Power valves to make sure they are fully opening at the higher RPM. Also, make sure your pipe and muffler are clear.
👍
I have Lernt sooo much from watching you over the past few years Joe! you have solved Almost Every problem there is. Thankyou :)
- Could your problem have somthing todo with the Pipe?/Chamber clogged?
I would go for the crank seals, after checking the power valves
Bogging. Hmm. I remember bogging on another bike, but I don't remember what was wrong. It is always interesting to go through the process of finding out what is wrong with the bike and fixing it.
🙂👍
Wow a CR! Nice 👍
Make sure the main jet needle is correct size, also I have had composite floats absorb gas when old, the machine is 29 years old.
I had a 96 kx250 that ran identical to that. It ended up being the power valves not functioning properly
Joe, love your channel, this bike is worthy of a full engine rebuild try to source some good cases! Also this one is a keeper!
Beautiful bike, you really find nice ones...
Thanks for the video could there be a hairline crack in the carburetor making it suck air I don't know I've had that experience on a completely different machine but I don't know it's weird have a better day
If I had one a small hole would be much better than a crack, which will need drill at the ends to make sure it doesn't travel laterally.
yep, the same thing when I repair cast water lines,, drill a hole on each side of the crack, tap the pipe till the crack reaches the holes, then clamp it...
Its not the jetting. Could be bad cdi,Coil, stator, yes or power valve not opening. Its not crank seal. It would rev up n down very weird. Like revs stay high for long like running lean. My guess is stator as ive had this same problem and it fixed it. Also i tested the stator on multi meter and it was fine. Shop told me to replace it and promised me it would solve it. Well obviously it worked. Oh yeh ktm still suffering with this problem. That jb weld needs looking at tho. Im not convinced there is air sucking in by listening to the engine tho
See what s up the JB weld.
IMHO always a RED FLAG - run away
Why can't jb weld fix it?
Not for this occasion, but for hard starting,and especially big bores, tilt the bike on it's side until you see gas overflow, put the bike in gear and rock it back and forth. Fuel is sucked into the engine and really helps promote firing. 2 strokes only, unless you want cam chain and valve timing problems. As a long term CR500 Honda owner and rider in all weather conditions, this really saves your right leg and all of it's components.
Vinny just called me and said...David please tell my owner...I am 1000% sure it is the ignition...CDI...coil...I don't want to be near the backfires..😊
Get a stock coil
Check the power valves
Lol! I once worked on a bike a whole afternoon before I realized it had a sidestand switch preventing it from starting. I had the carbs off, plugs out, battery charging and all.
Look at the baffle material in the silencer
My bet is you will find the slide needle and the emulsion tube are worn where they vibrate around while the engine is running at mid to top end . I have found this many times over the past 50 years most recently on a IT490 K which I junked the carb and put a new carb on it and it was great .
Yo, dude. What is up with your granddaddy’s GoldWing! Don’t leave me hanging. Please ASK ME ABOUT THE DIAMOND PLATES!
I been thinking the same thing
ive still been wondering about the tecate 3 he had.
Sounds like it’s never getting into the power band. I’d check the power valve. I assembled a power valve incorrectly in a KDX once and had a similar issue. Good luck!
I remember when I could read jet #s without using glasses a flash light and magnifying tool.
😂😂😂😂😂
How old are you?....Just wanting to know when to expect it...😂
@@brainstain22 I'm almost 60... starts in your40s
I'm 42 this year....lol. Damnit....I'm getting old. 🤣
I’m 63 and need all those tools to read tyre sizes nowadays 😢😢
Check for air leaks or obstructions in the exhaust. Ive had bith cause issues and make jetting next to impossible.
I had this same issue with a 91 cr125r and i couldnt ever figure it out to the point i just sold it.
That’s sad
@jayjudd6518 o well got a 01 kx250 with the money from it so 🤷 win win someone got the cr they wanted and I got the bike I wanted
Yea that sucks i had same problem yz125 2003 i changed all crank seals an i finally bought lectron carb an its fix it junk ass mukui carbs suck i love lectron carbs an apex head @@MrKawie1001
You should also check the jet block gasket. If someone was chasing a carb issue and dipped the carb, sometimes the dip eats the jet block gasket.
a clean machine!...Thanks for the carb class...how about change the crank seal next...
I thought it was rich but it wasn't but I also first thought PV at the first of the video, real fighter here. Been watching you're vid's forever and watched you turn into a top Tech!!!!!!
Man I buddy had one just like that and that thing was a handful but very fast
Check the spark plug cap. Honda uses a resistor cap 5 ohms max. If ohms is 10 or higher with cause a retarder ignition. Also could be stator one coil runs the high revs after 5k rpms . In my opinion it's a timing issue. Cap is a issue I have come across many times. I am 58 years old. Been riding and wrenching for 50 years...
Holy crap..Great deal on this bike..even if it has problems..vintage Hondas are hot commodities now .
Bog can be lean, rich, bad reeds, burning other fluids or bad ignition. Idle down sounded lean, but it runs worse when fatting the mains?🤔And better when thinning? Sounds like a lean idle circuit but a rich main. An air leak would be helped by fatting the jets not thinning so I don't think you have an air leak but you need to do a leak down test to confirm. Leak down tests are a MUST! The needle clip is stock at second from top but is it the correct needle? Plugs looked rich but not too rich but they were way too wet. I think you have an ignition problem or the carb itself is faulty. I had one on my Yamaha TZR 250 that ended up being the flywheel/rotor.
EDIIT: Check the exhaust pipe for fuel. If you have fuel in the pipe your ignition system is the problem. Its not firing as often as it should and fuel is getting thrown out the exhaust port. Also yes the PV could be the problem too. Check that the pully was not put in backwards. Its common with the Yamaha RZ350.
You got a great deal on that one!!!
Nice bike . I’m a Honda man !! Love ur content . U have help me on here understand more on bikes as I just bought 2 . Thanks keep up the videos dude !
Oh heck yeah I loved that bike same age as me
CRV valve....... always underestimated. clean & smooth as well as tight seat is key here. they screw with the air flow big time when the work sliw
52 pilot on these hondas is what we ran.
I once had a Yamaha 200 2 stroke 2 cylinder, as a boy of 14/15 year old, and at one point you had a mechanism on the ignition system with, when the engine made more rpm, the spark was made earlier by adjusting the moment that the points were opening. The ignition time was changing with more or less RPM.
Now did I buy a complete little set and I just put it on, and the engine did run but did not have the higher rpm anymore. Same as with your bike.
I also changed the carburetor, the exhaust pipes, and so on. He had more rpm when I made it leaner, but no power on the top....
I sold the thing before I found that.
Then I got a Yamaha YZ250 from I think from around 1985, and there I got the same problem when I got trouble with the engine.
The top of that Ignition changer was put on exactly the wrong way, so the ignition time didn't change but stayed the same all time.
Again bought it in original parts of Yamaha and I think the did the same thing again: assembled it exactly wrong.
I took the top of and turned it 180, so the time changed by more RPM and the problem was gone.
It is a bit silly explained, but I am dutch and not very well know with the technical terms in English.
I think it is about timing...