I was having low power from my saw as I tried to figure out what was wrong. My saw is the same model as this one. I spent the day cleaning the carburetor and not cutting wood. I saw your video and checked the screen on the exhaust and found it to be plugged just like the one you showed in video. At first soap and water, that didn't work, tried alcohol, didn't work. I used Lucus injector cleaner, it worked well. Thanks for sharing the tip, it saved downtime and didn't need to take it in for repair at shop.
Of all the videos I have watched on chainsaw tuneups not a single one of them has mentioned this filter on the exhaust. Thank you for getting this information out there.
Instant results on my Stihl MS 180! I had changed the fuel filter, air filter, mixed fresh fuel, installed a new spark plug and then stripped and cleaned the carb but to no avail. Checked the spark arrestor screen after watching your video and found it to be plugged solid, just as in your video. Cleaned up the screen with some carb cleaner and now the saw runs like a charm. Certainly appreciate you sharing this tip for trouble shooting. Cheers.
Over revving a cold saw especially without a bar and chain installed can cause a "cold seizure"as the piston will expand faster at the exhaust port.Always allow the saw to warm up first.
My MS170 was only two years old and started bogging down at higher speed settings. Didn't think your fix would apply to such a new saw but it was the solution! Thanks for the great video!
Great advice on something I never thought to check. I have a similar model mine is the MS 250 and it is starting to bog a little occasionally so I'm going to check to see if mine has this screen as well. Thank you
It’s also good to keep in mind never to run the saw too long or at all without that bar and chain on and tensioned properly. Not only could you over heat and over rev the engine but it can cause very expensive irreparable damage in the long run. Cheers!!
Speaking of the bar - flip the bar over everytime the chain gets removed. Helps keep the wearing of it distributed to both sides. When re-attaching the bar, put a slight upward pressure on the bottom of the tip of the bar while tightening the it.
What ‘very expensive irreparable damage’ would it cause? Why do you think the engine would overheat? You also can’t over rev the engine, short of just holding it wide open for a long time. Chainsaws are designed to rev, and newer ones all have limiters in the ignition. It’s a 2 stroke engine, not 4 stroke.
Straight to the point! Well done, no music you didn't introduce us to your dog or your kids, though I am sure they are great but I just wanted to know how to tune my saw up and that's exactly what I got.
Thank you ! I'm a handyman guy and occasionally I've done some backyard mechanic stuff for over a half century. I've worked on all kinds of motors, but never had I come across a motor that uses some little screen over the exhaust. I had looked all over the internet to try to figure out why my small chainsaw was bogging down. Who would think there would be a little screen completely clogged with carbon. I cleaned it off and it's running great now, especially because I put a new spark plug in it. It's just a little Stihl ms150c that I use for cutting branches. Using my larger Stihl for that wears me out. Thanks again.
This is fantastic advice! I have the same model chainsaw and after I cleaned the screen and the deflector, it ran like a charm. Thank you for this valuable knowledge.
Hey good job on finding the problem! Carb, ignition, and plugged fire screen all yield the same issues with these engines. I'm a mechanic on saws as well and carb or plugged fire screens are the most common problem. And the plugged fire screen is normally caused from the customer not running the saw full throttle, or like you mentioned running to much pre-mix. Have fun!
Gonna check my exhaust next. Rebuilt a Walbro carb on a $5 yardsale Mac 3200 today. Got it started (amd smiled) and seems to run real well (till ya try to start cutting wood). Bogs bad. Step 2... Learn proper jet settings. Step 3... Maybe go back and adjust the needle valve lever thingy properly. I think it may be a little off still. Walbro 247 = .65 - .70. But first... exhaust. Finger crosses and the wood is ready.
It's a "spark arrestor". I cut logs for 22 years and they tend to clog up on you. It was something that you can do without. The reason we had it was because the worker's insurance demanded we have it . They would check it randomly . But if you take care not to cut wood with the muffler too close , you can just take it off. It is meant to prevent sparks from the muffler to which to this day I have never seen happen.
I thought the spark arrestor was to prevent forest fires, not to appeal to some arbitrary insurance issue. There's a reason the insurer wants it there, for liability. Just because one person never started a forest fire, doesn't mean it can't happen.
Nice,got them work immediately. I have Stihl 170 and 290, both of them had no power and hard to keep them running idle. I opened the front screens , both of them clogged. I did not have new screens and they are hard to clean, so I just got rid of them, when I get new, I put them on.
Good information.... also remember to check the fuel line in the gas tank. If regular gas is used, then it might have ethanol and that breaks down the rubber in the gas line over time.(94 contains no ethanol.)Then at high demand, full throttle, the line can collapse inside the tank and the saw bogs. Easy fix by simply replacing the line with new one. (I had to wait to have my new gas line delivered so in the meantime I used a steel spring from a pen as a stent in the line and it worked perfectly.) Stihl is a great little saw.
Great advice. My Stihl MS193T chainsaw would run great at idle, but bog down when trying to rev. I cleaned the screen on the exhaust and the problem is fixed! Thank You!
My Stihl MS 290 started bogging down when giving it gas & with no load (not cutting). I tried all the basic stuff,.. fuel, carb setting, air filter, spark plug,... nothing. I pulled the muffler filter and it was basically 100% clogged. I cleaned with carb cleaner and a wire brush, put it back in.... & the saw runs like it was new. I would have never thought of this simple fix if I did not watch this video. Thanks!
Great video - Thanks for your help. I have a Makita DCS520 that kept bogging. Was skeptical at first as I am in New Zealand and didn't think I would have the screen. Sure enough it was clogged up. Pulled it out fired it up and ran like a dream. Very thankful for everyone taking the time to post videos like yours to help others.
I run a bunch of Stihl power tools daily in a commercial setting. We always take the spark arresters out. The eventually clog up irrespective of a correct mix or not. We absolutely mix the correct ratio. My guess is, they only put those on for liability reasons. Maybe so Stihl dealers can make minimum 30min- one-hour labour charges and diagnosis fees for a two minute job, for something very obvious to those who know.
Wow! Wide open throttle on the initial start???? Obviously you forgot that it's air-cooled and the only lubrication for that tny piston comes from the fuel mix. Brilliant!
Thank you !!!! This video did the trick for my Husqvarna 51L. Took off the muffler, cleaned it and the screen and it runs like a champ! Thank you again!
Great Video. Since its Spring, I went to check on my chainsaws. 2 out of 3 are having trouble staying running. Fresh gas and oil mix. Fresh spark plugs. Now, thanks to this video, I'll be looking at that mesh screen. And periodically clean it after x amount of uses.
Great tip! I was ready to junk mine over this little issue. Went over everything and couldn't find the problem until I watched this video. Thanks for the help! Runs great again.
Thank you very much! Was cutting with my husky and it didn't want to cut it was bogging. Did everything even considered buying tool to adjust L and H settings. Then I found your video and first thing I did was took this wire mesh off and cleaned it. Now its going like a beast and no problems.. Very helpful! Thank you. You get a like from me :)
Great video on the importance of checking the spark arrestor screen. An often overlooked piece on a chainsaw by many. It was nails on a chalkboard for me to hear you peg and even briefly hold that throttle just after starting. If this becomes a users habit it will lead to cold seizure scoring of your piston & cylinder. Newbies & construction guys (infrequent users that just wanna get to cutting once started) are notorious for cold seize scoring a chainsaw. Let your chainsaw warm up before pegging that throttle, ladies & gentlemen. It will keep its power we & last much longer if you do. That holds true for any motorized device including your vehicle.
Foxboss9 is right about fuel. Not only should it be keept fresh, but at the right ratio. I had problems with my 42cc Poulan saw bogging after running wide open for 20-30 sec. I fashioned a tool to adjust the carb (I'm pretty expert at tuning). It ran much stronger, but still bogged after running wide open for 20-30 sec. I made a batch of fresh fuel at 35:1, though the engine calls for 40:1. That did the trick. It now smokes a bit (no smoke is not healthy), runs super strong, and never bogs. Man, that saw cuts like it's angry now. When you have 3 or 4 2 stroke tools calling for 30:1 through 50:1, you have to be careful. Label your fuel cans!
If you only use chainsaw once in a while; only use ready mix gas and oil sold at Canadian Tire or at your local chainsaw dealer. It has high octane and has a shelf life of 2 years, no more problems with your chainsaw gumming up after that.
In Ontario Canada, Premium fuel at Shell Stations does not contain Ethanol. Best choice for 2 strokes and show cars that are not used in Winter. Excellent video.
Your tips headed me in the right direction for a bad bog problem. Had some gas in the saw that was ??? despite having a date on it with stabil fuel additive in it. Replaced the fuel with fresh fuel and it eliminated the bog completely.
contacted stihl about the arrestor screen for a Stihl 171 and had a reply back The MS 171 supplied in the UK does not have an arrester screen as they were only available in the product version MS171-Z which were supplied in Australia, USA and Canada.
Just typed in stihl chainsaw loosing power and this came up. Funny enough I have the exact same saw. Watched the video and that was my problem. 10 min later I'm up and running again so thank you.
You did an excellent trouble shoot from A to Z or really from A to X. You still have to put the bar and chain on and cut a moderate sized piece of wood to be certain of high speed mixture. I bought a barely used bigger brother to that saw, the ms250, and it's a beautiful thing to run.
+Foxboss9 I have to ask you what gunked up that arrester screen like that? I run echo 2 stroke oil by the gallon and I really never clean a screen at all. heck it looked like someone was old school running a 16 to one mixture?
+Burt Hulbert could be.. Even ISO LEG-D stuff like Echo oil will clog up if it sits in the tank for a year to a year and a half.. The gas may evaporate but the oil remains.. Just Normal customer abuse..
@@burtvhulberthyhbn7583It shouldn't gunk up if it's regularly run at full throttle. If it spends a lot of time idling or just sits with gas in the tank, then you'll start having issues.
Thank you... Just went through the carb, New cleaner, spark plug.. Still holding an idle, but bogging and both low/high adjustments doing nothing. Never would've thought to check the exhaust, she's happy now.
I had another cause of bogging out that I’ve fixed. I accidently used chain oil in the fuel instead of T2 engine oil. The engine run at idle but bogged out at high revs. When I put the right fuel in it was OK. I went through all of the cleaning and adjusting processes it was only when I tried a new mix of fuel that I realised the fuel in the tank was yellow, the only T2 oil that I have is pink but both bottles are black and look the same. All the best . . . Andy
Posting this around because I couldn't find anybody else online talking about it: After having a world of trouble with my Stihl MS-250 not starting, I decided to check the coil. It had spark, but I guess it wasn't strong enough to fire the plug. Forums have people that tell you to replace the coil in a case such as this, but a few say the coil seldom goes bad in a Stihl. My saw is not that old. Even so, I decided to pull the coil and replace it with one out of another older ms-250 I have. Then I noticed the gap between the old saw's coil and flywheel. It was not the same as the one on the problem saw. The non-starting unit had a wider gap. I got back online and found the correct gap setting should be 25 thousandth (can use a business card to set the gap). I decided to only remove the coil and clean it up, then reset the gap. I put everything back together and used a business card to set the gap. Then pulled the spark plug and made sure it was gaped at 25 thousandths too. The saw fired up and runs like new! It's hard to understand how that gap changed. It was never torn down till now, and it used to run very well for the longest time. Maybe buildup from the dust and oil lodged between the two components and caused it? But the torque screws holding it in place were very tight, and I can't see any reason for the coil to have slipped. But now happy... got my toy to working again.
mine would start cold no problem but if it would if it ran for a minute it wouldn't start for a couple hours was the coil. how does Chinese one minute so I spent nine bucks & stuck another one in it again
Very true! However, one thing you could try would be to remove the spark arrestor for testing purposes only. Your test period may be 5 minutes, or may be an indefinite test period. Some places (national forest, etc.) will require them (and check for them.) Not just on a chainsaw, but a dirtbike, etc. etc. etc.
I had similar problem with my leaf blower (also a Stihl in my case). It started but ran roughly and had low power. Such an easy thing to check and fix - it simply unscrews. Cleaned by soaking in gas and gentle fine wire brush. Now a part of my annual clean/maintenance.
Not to be critical but u should let it warm up a bit b4 u run it wide open like that. Give that piston bore a chance to expand a bit. Outher than that thanks for the vid.
I needed this video about 4 years ago.. lol.. I bought a Remington back in 2013 used it for wood cutting, then skipped a year, using just my electric heat.. 2015, I got the Remington out and it wouldn't start very well, finally got it to start then by holding the choke open a little it would idle but if I tried to throttle it. It would die. I just went out and bought a Kobalt 80volt electric. No more gas/oil mix or yanking on ropes.. Anyway good video.. BTW, I sold that other saw for $1.. The guy later said that he couldn't get it to run either.. If I see him, I'll pass this info on to him to check this.. or I might try to buy it back for 50 cents.. lol (he was my cousin or it wouldn't have been $1)
I have a decent 044 and it started bogging down after cutting a few cords of wood. Took it into a local saw shop. He said he was going to. Retune the carb real fast. He used an allen wrench. First off its a flat head screw on the carb. He said i needed a new carb. Would cost me $100. Went home and retuned the carb right. Runs great.
My ms170 was bogging down. I was afraid it was a carb or compression problem. Searched the RUclips and watched this video to diagnose. Turns out the spark arrester was filthy. I didnt even know chainsaws had spark arrestors until I watched this video. Cleaned it and it runs like a top now. Thanks!
Thank you for the info. I’m having an issue with a new saw. Starts fine. Used it for 30 minutes, shut it off to refuel, restarted fine. But now it won’t take any throttle at all. I’m assuming it is a carb adjustment issue and I’ll have to either attempt adjusting the saw, or take it back to the seller for adjustment?
the spark arrestor screen can clog from user error as well, not always too rich. users at work have been able to clog screens, usually only after 2-3 seasons. the fuel they run is ethanol free, stihl ultra 50:1. once you run an engine with plugged screen you never forget the characteristics. probably not the best idea to free rev that cold engine at initial start up.
Stihl MS170 and 180's are notorious for this problem. The carbs are non-adjustable and often run a little too rich. This results in blocking of the spark arrestor with the oil in the exhaust. I remove my arrestor and only reinstall it for summer use, when fire is a worry.
I read thru all replies and got my answer about mix ratio. 40:1.....husky are 50:1.... I have one of each so I'm going do write it on saw so I don't forget. While the husky is bigger engine, the stihl is lighter weight. I'm liking the stihl better. Arms not as tired after cutting all day! Cuts like butter with sharp chain.
If it's not the spark arrestor that's clogged it can either be the fact that the carby needs adjusting or that the carby has an air leak in it. I bought a crappy carby on EBay for a Stihl hedge trimmer that I rebuilt for someone that had air leaking around the 1 way check valve for the main jet,it was a poor fit inside the carby body & the fuel ate away the Loctite & where it previously ran good,the hedge trimmer returned with running problems,I can tell by placing the carby inside a jar of water with the hose attached to the fuel supply & applied air pressure to the hose then found out that air was leaking from around the check valve. I ordered another one for $30 AUD & it ran as good as gold. I had to carefully isolate the problem because the caretaker who used that 2 stroke lawn equipment literally poured 2 stroke oil into the fuel tank without measuring it. That's why a lot of the Stihl leaf blowers I repaired of theirs needed their spark arrestor screens cleaned as that caused them to Lack power. I burned the carbon out of them with a propane torch,normally you shouldn't have to because Stihl recommends a 50:1 fuel to oil mixture which means that the exhaust is virtually smokeless !!!!
SPARK ARRESTOR!!!! Why don't you know that? In the Western third of the US, where conditions are generally much drier, the SPARK ARRESTOR is usually REQUIRED by forestry and conservation agencies. For most of us, spark arrestor maintenance is part of the program. Basucally a good and useful video. Thank you.
I just bought an 87 homelite for $2 from the junk yard. Shot some carb cleaner though the intake and it fired 2nd pull. New carb rebuild, new magneto, new spark plug, half the bolts were loose, and it was just buried literally to the handle in the mud in a scrap pile. My guess is they had issues with it not running under WOT, tore it all apart and changed everything, then just gave up when they couldnt figure it out. Their loss, my gain. I got a practically free bright neon orange saw😂
When I'm done using my saw and I'm not going to use it for a while I always pour out the fuel and run it til it runs out of gas that way when I get ready to use it next time I can put in fresh fuel. Saves a lot of headaches later.
Fantastic insights and a great video, Now my interpretation: gGet rid of the screen, put it in the garbage and reassemble and never worry about that again.
Depends on saw, exhaust screen, spark plug, good clean fuel, air filter clean, been sitting carb cleaning, inspection. Runs bit funky carb possibly, then adjusting like here...
I guess I just fixed mine by removing the muffler and cleaning the screen. I had tried the low/high speed adjustment and only when I did this did it start to work. Thanks.
the little holes before the spark arrestor screen is the part where I drilled bigger holes and where the little fins are on the exhaust ,I bent them out a little more, for better flow. And one more good tip is the combustion bowl would be so caked by looking at that screen. Take out the plug and spray that head cleaner or tune up in a can . put the plug back in and dont put the plug wire on it . pull it a couple times slowly and let it sit for awhile 30 min. approx. then take out the plug and spray some starter fluid on the plug Pt. put it back together and start it up and watch all these chunks of old hard carbon fly outta your muffler. Ive done this to so many motors that wont run well. Might have to clean the exhaust again because of all that crap might not make it out with the screen and small holes. Runs like just bought most of the time.
Over time that screen (spark arrestor) can rust apart and pieces could find their way into the cylinder. I blew a saw that way a few years ago. Chuck it. Thumbs up for the vid.
good video but these saws have very poor carbs on them i remove them and put a fully adjustable carb on and the saw runs so much better more power and no bog but after installing the new carb you need to set the rpms on it to factory settings the old junk carb you just throw it away. the new carb is a Stihl carb costs $28 and it fits the 025 saw but will fit the 170-180 I have done hundreds of these swaps it turns the saw into a real saw
Stihl dealer is where you get the carb the part number is 1123-120-0605 and there is a couple things you need to do to it but its very easy first the pulse hole in this carb has 2 holes one is plugged you need to remove the small brass plug best way drill it then use a pick to pick it out next you will need to slot the butterfly rod out i use a cut off tool takes 10 seconds and your done the new carb just has a hole in it grind the slot in for the throttle rod then install carb just like the old one then you will need to put a litte rtv in the filter housing where the little round vent on the old carb went into air cleaner then put it together there are jet adjustment holes in air cleaner box already then you will need to drill a new hole in the handle for idle speed screw i just eye ball it then you will need to put a small slot in the housing so you can adjust the jets when the top cover is on very simple use a drill or cut off wheel then your done fire it up set the high and low speed jets now take it out and cut with it way more power and no more bogging down its very easy it takes me 5 min to do the whole job
When I was a teen my dad had a monster Lombard Comango which we would cut cords and cords of wood every year in Maine with, he never ever got a chance to show me how to tune it, just sharpen it!
I throw those spark arrestor screens in the trash. nothing but trouble have fixed many saws and weed trimmers and leaf blowers with the same problem they run great after doing so. its funny how people think its fuel related a lot of times when its a plugged muffler screen or exhaust ports on a 2 cycle engine
Hi Foxboss9, I just replaced the rotted off clunk/fuel line. Thought that would make her run. Nope, runs, but the top end dies out. I run 32:1 gas/oil mix, so your idea of the exhaust screen may be the problem, I will try that next. Gas is two weeks old. I run 2 stroke "Chain saw engines" on my large radio control warbird aircraft, so have a fair amount of experience with these engines. I have run 32:1 to great success, for over 5 years. So, this poulan engine ran great 2 months ago. A couple of weeks ago, I tried it, and blah, hardly ran. Could be a combination of errors such as dirty fuel screen in the carb. Engine is 7 years old and has run great up till now.
lbjlbj1 all stihl products run 50:1 period, youll end up frying the piston and cylinder and it will not take long. first sign is your gonna start loosing compression
curtis kitchens that is what Stihl recommends using their oil... Better mix oil such as Echo's ISO-LEG-D rated oil can be used at a lesser ratio. These guys aren't worried about warranties on their old saws. MFG recommendations are just that. For every saw that has burned up there are 20 doing fine. Just like no load full Rev.. Fuel limitation based on carb design will not allow a well tuned engine to scatter if it's wound up to it's upper limits.. For every one that has come apart there are 70 that don't experience I'll effects. Theoretical operation standards are rarely the actual abilities. I listened to all the Mfg's during all my training over the years and found that they all are teaching what is in the best for the MFG and never, ever what you can get away with. With the exception of Echo's advanced failure analysis class in which they have shown that you can run their cheapest string trimmer on straight gas, at full throttle for over an hour (refill on the fly) and will continue to run. It will be damaged but can be done. Showing that with a very minor amount or oil in the mix it will do the same thing without damage. But obviously they don't recommend it.
Why I like buying the premix out of the can good for 2 years. How often does a home owner cut wood . Shut off leave it until who knows when . 20.00 Gal it is worth it . Keeps it nice clean. I just picked up 2 Echo CS340 and 440 at a recycle center just need to clean carb out.
A plugged spark arrestor is a common problem. My advice would be to just throw the thing away. Don't even try to clean it!! Another tip is to use non ethanol fuel with 2 ounces of sea foam per gallon of gas. Ethanol based fuel in time, will destroy a carburetor. Taking this advice, you will never have a fuel related problem again!!
+DR Dan there is an alcohol formulation in Seafoam. However, over 30 years, I personally never had, nor have I ever heard of any negative incident or effects of using Seafoam on any level with any engine (small or automotive). Using Seafoam as a cleaner or fuel additive(running/storage) will not harm components if used correctly (even incorrectly in some cases). The stuff just works.
![KSI - Dirty [Official Visualiser]](http://i.ytimg.com/vi/VoDh1h1dPUE/mqdefault.jpg)
I was having low power from my saw as I tried to figure out what was wrong. My saw is the same model as this one. I spent the day cleaning the carburetor and not cutting wood. I saw your video and checked the screen on the exhaust and found it to be plugged just like the one you showed in video. At first soap and water, that didn't work, tried alcohol, didn't work. I used Lucus injector cleaner, it worked well. Thanks for sharing the tip, it saved downtime and didn't need to take it in for repair at shop.
Cole B yu spent the day cleaning a carb.. don't quit yur day job
Next time try to use carb cleaner and it should be OK
How to start a chain saw?
"big ass puss" People like you dont quit their day Or night jobs.. They get fired!
next time it clogs up chuck it in the trash that’s where they belong.
Of all the videos I have watched on chainsaw tuneups not a single one of them has mentioned this filter on the exhaust. Thank you for getting this information out there.
Instant results on my Stihl MS 180! I had changed the fuel filter, air filter, mixed fresh fuel, installed a new spark plug and then stripped and cleaned the carb but to no avail. Checked the spark arrestor screen after watching your video and found it to be plugged solid, just as in your video. Cleaned up the screen with some carb cleaner and now the saw runs like a charm. Certainly appreciate you sharing this tip for trouble shooting. Cheers.
Over revving a cold saw especially without a bar and chain installed can cause a "cold seizure"as the piston will expand faster at the exhaust port.Always allow the saw to warm up first.
My MS170 was only two years old and started bogging down at higher speed settings. Didn't think your fix would apply to such a new saw but it was the solution! Thanks for the great video!
Great advice on something I never thought to check. I have a similar model mine is the MS 250 and it is starting to bog a little occasionally so I'm going to check to see if mine has this screen as well. Thank you
It’s also good to keep in mind never to run the saw too long or at all without that bar and chain on and tensioned properly. Not only could you over heat and over rev the engine but it can cause very expensive irreparable damage in the long run. Cheers!!
Speaking of the bar - flip the bar over everytime the chain gets removed. Helps keep the wearing of it distributed to both sides. When re-attaching the bar, put a slight upward pressure on the bottom of the tip of the bar while tightening the it.
What ‘very expensive irreparable damage’ would it cause? Why do you think the engine would overheat? You also can’t over rev the engine, short of just holding it wide open for a long time. Chainsaws are designed to rev, and newer ones all have limiters in the ignition. It’s a 2 stroke engine, not 4 stroke.
Straight to the point! Well done, no music you didn't introduce us to your dog or your kids, though I am sure they are great but I just wanted to know how to tune my saw up and that's exactly what I got.
Thank You!! My 15 year old son watched your video, and now the chain saw is working great!
That is great!
+Paul L: A 15 year old boy is too young to be handling a chain-saw.
All depends on how he grew up...IMO
Lol did you grow up in a bubble? Or just i Citydiot @@johnd942
Thank you ! I'm a handyman guy and occasionally I've done some backyard mechanic stuff for over a half century. I've worked on all kinds of motors, but never had I come across a motor that uses some little screen over the exhaust. I had looked all over the internet to try to figure out why my small chainsaw was bogging down. Who would think there would be a little screen completely clogged with carbon. I cleaned it off and it's running great now, especially because I put a new spark plug in it. It's just a little Stihl ms150c that I use for cutting branches. Using my larger Stihl for that wears me out. Thanks again.
The mesh screen is a "Spark Arrest" preventing sparks from flying out the exhaust in a dry environment ;)
Well explained Basic Maintenance Thank you for sharing The mesh is a spark arrestor for use in high risk Fire areas Dry forestry, Sawmills Etc
I had crap old fuel. As an amateur I never had realised this could have such a profound effect. New fuel, works a dream, thank you!
This is fantastic advice! I have the same model chainsaw and after I cleaned the screen and the deflector, it ran like a charm. Thank you for this valuable knowledge.
My teenage years of cleaning my pipe and bong screens have prepared me for this exact task.
+Robert King And there it is..Best comment!!
Robert King LMFAO
So, how much does it help ?
Robert King hahahahaaa!!! IK-R?
like a boss
Hey good job on finding the problem! Carb, ignition, and plugged fire screen all yield the same issues with these engines. I'm a mechanic on saws as well and carb or plugged fire screens are the most common problem. And the plugged fire screen is normally caused from the customer not running the saw full throttle, or like you mentioned running to much pre-mix. Have fun!
Military Chevy or running CHEAP MIX OIL. run full synthetic it wont plug up
Gonna check my exhaust next. Rebuilt a Walbro carb on a $5 yardsale Mac 3200 today. Got it started (amd smiled) and seems to run real well (till ya try to start cutting wood). Bogs bad.
Step 2... Learn proper jet settings.
Step 3... Maybe go back and adjust the needle valve lever thingy properly. I think it may be a little off still. Walbro 247 = .65 - .70.
But first... exhaust.
Finger crosses and the wood is ready.
Thanks for getting and keeping it to the point without wasting time showing me where the dog sleeps.
Brother you saved me $45 and taught me a new skill. Thank you 10 time over.
It's a "spark arrestor". I cut logs for 22 years and they tend to clog up on you. It was something that you can do without. The reason we had it was because the worker's insurance demanded we have it . They would check it randomly . But if you take care not to cut wood with the muffler too close , you can just take it off. It is meant to prevent sparks from the muffler to which to this day I have never seen happen.
Antonio Arellano run full synthetic mix oil it wont plug up. run the cheap stuff it will plug up because it has crude oil in it
i would think if it was throwing sparks it would be a good sigh of the saws engine starting to die.
The sparks are carbon, not metal.
Good info! Thanks for your input. Experience will always win.
I thought the spark arrestor was to prevent forest fires, not to appeal to some arbitrary insurance issue. There's a reason the insurer wants it there, for liability. Just because one person never started a forest fire, doesn't mean it can't happen.
Nice,got them work immediately. I have Stihl 170 and 290, both of them had no power and hard to keep them running idle. I opened the front screens , both of them clogged. I did not have new screens and they are hard to clean, so I just got rid of them, when I get new, I put them on.
Good information.... also remember to check the fuel line in the gas tank. If regular gas is used, then it might have ethanol and that breaks down the rubber in the gas line over time.(94 contains no ethanol.)Then at high demand, full throttle, the line can collapse inside the tank and the saw bogs. Easy fix by simply replacing the line with new one. (I had to wait to have my new gas line delivered so in the meantime I used a steel spring from a pen as a stent in the line and it worked perfectly.) Stihl is a great little saw.
Thanks..good points for sure..
If you're spark arrestor is clogged like that, your mix is too oily, and exhaust port needs cleaning 🧐
Great advice. My Stihl MS193T chainsaw would run great at idle, but bog down when trying to rev. I cleaned the screen on the exhaust and the problem is fixed! Thank You!
My Stihl MS 290 started bogging down when giving it gas & with no load (not cutting). I tried all the basic stuff,.. fuel, carb setting, air filter, spark plug,... nothing. I pulled the muffler filter and it was basically 100% clogged. I cleaned with carb cleaner and a wire brush, put it back in.... & the saw runs like it was new. I would have never thought of this simple fix if I did not watch this video. Thanks!
Nice job. Had same issue. Chased other issues for hours before finding this cause. Thanks for sharing. Well done.
Great video - Thanks for your help. I have a Makita DCS520 that kept bogging. Was skeptical at first as I am in New Zealand and didn't think I would have the screen. Sure enough it was clogged up. Pulled it out fired it up and ran like a dream. Very thankful for everyone taking the time to post videos like yours to help others.
I run a bunch of Stihl power tools daily in a commercial setting. We always take the spark arresters out. The eventually clog up irrespective of a correct mix or not. We absolutely mix the correct ratio. My guess is, they only put those on for liability reasons. Maybe so Stihl dealers can make minimum 30min- one-hour labour charges and diagnosis fees for a two minute job, for something very obvious to those who know.
Wow! Wide open throttle on the initial start???? Obviously you forgot that it's air-cooled and the only lubrication for that tny piston comes from the fuel mix. Brilliant!
Thank you !!!! This video did the trick for my Husqvarna 51L. Took off the muffler, cleaned it and the screen and it runs like a champ! Thank you again!
You're a star, mate! Thanks. Exhaust was the problem. Shared knowledge is what makes the world go round. Thanks again.
great news! thanks for watching😀
Amsoil synthetic two stroke oil at 100/1 mix ratio and high test fuel is your best way to go on these saws ! Never had a screen clog problem!
Thanks heaps, great video, straight to the point! Clogged screen is now clean and MS170 is going great again.
And always full throttle immediately! Especially when it's super cold out !!!
You must be a chainsaw salesman..i was waiting for the saw to cold seizure..always let the saw warm up, before beating on it..lol
sarcasm... tee hee.
Great way of seizing up the piston in the saw !!
Thanks for the concise video. I fixed my saw in minutes!
A great video have run saws for 40 years with Hydro and personal business. Thank you.
Great Video. Since its Spring, I went to check on my chainsaws. 2 out of 3 are having trouble staying running. Fresh gas and oil mix. Fresh spark plugs. Now, thanks to this video, I'll be looking at that mesh screen. And periodically clean it after x amount of uses.
✅😁
This is the best and most informative video I've seen in some time! Excellent work!
Great tip! I was ready to junk mine over this little issue. Went over everything and couldn't find the problem until I watched this video. Thanks for the help! Runs great again.
Thank you very much! Was cutting with my husky and it didn't want to cut it was bogging. Did everything even considered buying tool to adjust L and H settings. Then I found your video and first thing I did was took this wire mesh off and cleaned it. Now its going like a beast and no problems.. Very helpful! Thank you. You get a like from me :)
Cool!
Great video on the importance of checking the spark arrestor screen. An often overlooked piece on a chainsaw by many. It was nails on a chalkboard for me to hear you peg and even briefly hold that throttle just after starting. If this becomes a users habit it will lead to cold seizure scoring of your piston & cylinder. Newbies & construction guys (infrequent users that just wanna get to cutting once started) are notorious for cold seize scoring a chainsaw. Let your chainsaw warm up before pegging that throttle, ladies & gentlemen. It will keep its power we & last much longer if you do. That holds true for any motorized device including your vehicle.
He did that to a customer's saw.
Unbelievable.
You have to at least do a throttle squeeze on Stihl if it is on the half-choke.
Foxboss9 is right about fuel. Not only should it be keept fresh, but at the right ratio.
I had problems with my 42cc Poulan saw bogging after running wide open for 20-30 sec. I fashioned a tool to adjust the carb (I'm pretty expert at tuning). It ran much stronger, but still bogged after running wide open for 20-30 sec. I made a batch of fresh fuel at 35:1, though the engine calls for 40:1. That did the trick. It now smokes a bit (no smoke is not healthy), runs super strong, and never bogs. Man, that saw cuts like it's angry now.
When you have 3 or 4 2 stroke tools calling for 30:1 through 50:1, you have to be careful. Label your fuel cans!
If you only use chainsaw once in a while; only use ready mix gas and oil sold at Canadian Tire or at your local chainsaw dealer. It has high octane and has a shelf life of 2 years, no more problems with your chainsaw gumming up after that.
+kodiak we don't have Canadian Tire in lower 48, especially in Alabama
davel8n I figured that much which is why I also mentioned your local chainsaw dealer ;)
kodiak could not agree more with you so many insist on 87 octane pump gas & don't understand that it's strictly an auto fuel
I use that canned fuel for all my 2 strokes. it's quite a bit more expensive but saves you a lot more money and time in the long run.
In Ontario Canada, Premium fuel at Shell Stations does not contain Ethanol. Best choice for 2 strokes and show cars that are not used in Winter. Excellent video.
Your tips headed me in the right direction for a bad bog problem. Had some gas in the saw that was ??? despite having a date on it with stabil fuel additive in it. Replaced the fuel with fresh fuel and it eliminated the bog completely.
Dave V Great! 😊👍
You should have run the saw with the bogging problem to show what it sounds like with the screen plugged.
Listen to the song "Lumberjack ". Forget who sings it....Jackle ?
@@anthonythorp7291 I havent jacked my lumber babaayyyy, since my chain saw youuuuuuuuuuuuu. lol yes Jackal.
Thanks for the video. I just inherited my dads chainsaw and now I know a lot more about it.
Arian Smith 😊
I love it when the first easiest thing to check is all that is wrong. Just checked mine and it was clogged bad, thanks for the video!!
Great video. Great info. Straight to the point and easy to follow. Great flow.
contacted stihl about the arrestor screen for a Stihl 171 and had a reply back The MS 171 supplied in the UK does not have an arrester screen as they were only available in the product version MS171-Z which were supplied in Australia, USA and Canada.
Just typed in stihl chainsaw loosing power and this came up. Funny enough I have the exact same saw. Watched the video and that was my problem. 10 min later I'm up and running again so thank you.
+cartelli50 great news!
You did an excellent trouble shoot from A to Z or really from A to X. You still have to put the bar and chain on and cut a moderate sized piece of wood to be certain of high speed mixture. I bought a barely used bigger brother to that saw, the ms250, and it's a beautiful thing to run.
👍😊
+Foxboss9 I have to ask you what gunked up that arrester screen like that? I run echo 2 stroke oil by the gallon and I really never clean a screen at all. heck it looked like someone was old school running a 16 to one mixture?
+Burt Hulbert could be.. Even ISO LEG-D stuff like Echo oil will clog up if it sits in the tank for a year to a year and a half.. The gas may evaporate but the oil remains.. Just Normal customer abuse..
@@burtvhulberthyhbn7583It shouldn't gunk up if it's regularly run at full throttle. If it spends a lot of time idling or just sits with gas in the tank, then you'll start having issues.
I like how within 2 seconds of starting it, you pegged the throttle and screamed her wide open. That's always good for a cold saw.
Old wives tale.. That's a 4 stroke issue
Thank you... Just went through the carb, New cleaner, spark plug.. Still holding an idle, but bogging and both low/high adjustments doing nothing. Never would've thought to check the exhaust, she's happy now.
tampabayrider Great News 👍
I had another cause of bogging out that I’ve fixed. I accidently
used chain oil in the fuel instead of T2 engine oil. The engine run at idle but
bogged out at high revs. When I put the right fuel in it was OK. I went through
all of the cleaning and adjusting processes it was only when I tried a new mix
of fuel that I realised the fuel in the tank was yellow, the only T2 oil that I
have is pink but both bottles are black and look the same. All the best . . . Andy
That was so helpful. Thank you. My local saw repair shop was going to charge me £70 UK. For what took me 20 minutes. Regards M
Great info... Dad always said it's the big three -air, fuel and spark ... Most fail to realize breathing = inhale AND exhale.
Posting this around because I couldn't find anybody else online talking
about it:
After having a world of trouble with my Stihl MS-250 not starting, I
decided to check the coil. It had spark, but I guess it wasn't strong
enough to fire the plug. Forums have people that tell you to replace the
coil in a case such as this, but a few say the coil seldom goes bad in a
Stihl.
My saw is not that old. Even so, I decided to pull the coil and replace
it with one out of another older ms-250 I have. Then I noticed the gap
between the old saw's coil and flywheel. It was not the same as the one
on the problem saw. The non-starting unit had a wider gap.
I got back online and found the correct gap setting should be 25
thousandth (can use a business card to set the gap). I decided to only
remove the coil and clean it up, then reset the gap.
I put everything back together and used a business card to set the gap.
Then pulled the spark plug and made sure it was gaped at 25 thousandths
too.
The saw fired up and runs like new!
It's hard to understand how that gap changed. It was never torn down
till now, and it used to run very well for the longest time. Maybe
buildup from the dust and oil lodged between the two components and
caused it? But the torque screws holding it in place were very tight,
and I can't see any reason for the coil to have slipped.
But now happy... got my toy to working again.
mine would start cold no problem but if it would if it ran for a minute it wouldn't start for a couple hours was the coil. how does Chinese one minute so I spent nine bucks & stuck another one in it again
In case anyone is interested that "screen" is the "spark arrester" and is required by federal law.
Very true! However, one thing you could try would be to remove the spark arrestor for testing purposes only. Your test period may be 5 minutes, or may be an indefinite test period. Some places (national forest, etc.) will require them (and check for them.) Not just on a chainsaw, but a dirtbike, etc. etc. etc.
I had similar problem with my leaf blower (also a Stihl in my case). It started but ran roughly and had low power. Such an easy thing to check and fix - it simply unscrews. Cleaned by soaking in gas and gentle fine wire brush. Now a part of my annual clean/maintenance.
;-)
Not to be critical but u should let it warm up a bit b4 u run it wide open like that.
Give that piston bore a chance to expand a bit.
Outher than that thanks for the vid.
Never rev a 2 stroke when you first start it. Cold lock = damage beyond repair.
I needed this video about 4 years ago.. lol.. I bought a Remington back in 2013 used it for wood cutting, then skipped a year, using just my electric heat.. 2015, I got the Remington out and it wouldn't start very well, finally got it to start then by holding the choke open a little it would idle but if I tried to throttle it. It would die. I just went out and bought a Kobalt 80volt electric. No more gas/oil mix or yanking on ropes.. Anyway good video.. BTW, I sold that other saw for $1.. The guy later said that he couldn't get it to run either.. If I see him, I'll pass this info on to him to check this.. or I might try to buy it back for 50 cents.. lol (he was my cousin or it wouldn't have been $1)
I have a decent 044 and it started bogging down after cutting a few cords of wood. Took it into a local saw shop. He said he was going to. Retune the carb real fast. He used an allen wrench. First off its a flat head screw on the carb. He said i needed a new carb. Would cost me $100. Went home and retuned the carb right. Runs great.
👍😁
Might also check the impulse line for cracks. Replace it if cracked or it won't idle/spool up right.
My ms170 was bogging down. I was afraid it was a carb or compression problem. Searched the RUclips and watched this video to diagnose. Turns out the spark arrester was filthy. I didnt even know chainsaws had spark arrestors until I watched this video. Cleaned it and it runs like a top now. Thanks!
Otto 81494 Great! Glad it helped out!
Thank you for the info. I’m having an issue with a new saw. Starts fine. Used it for 30 minutes, shut it off to refuel, restarted fine. But now it won’t take any throttle at all. I’m assuming it is a carb adjustment issue and I’ll have to either attempt adjusting the saw, or take it back to the seller for adjustment?
the spark arrestor screen can clog from user error as well, not always too rich. users at work have been able to clog screens, usually only after 2-3 seasons. the fuel they run is ethanol free, stihl ultra 50:1. once you run an engine with plugged screen you never forget the characteristics. probably not the best idea to free rev that cold engine at initial start up.
Screen is a spark arrestor.....and can be the primary reason it bogs. Nice Video!!
Thanks for sharing this tip. I would never have thought to check that screen.
n124lp 👍😁
Stihl MS170 and 180's are notorious for this problem. The carbs are non-adjustable and often run a little too rich. This results in blocking of the spark arrestor with the oil in the exhaust. I remove my arrestor and only reinstall it for summer use, when fire is a worry.
I read thru all replies and got my answer about mix ratio. 40:1.....husky are 50:1.... I have one of each so I'm going do write it on saw so I don't forget. While the husky is bigger engine, the stihl is lighter weight. I'm liking the stihl better. Arms not as tired after cutting all day! Cuts like butter with sharp chain.
If it's not the spark arrestor that's clogged it can either be the fact that the carby needs adjusting or that the carby has an air leak in it.
I bought a crappy carby on EBay for a Stihl hedge trimmer that I rebuilt for someone that had air leaking around the 1 way check valve for the main jet,it was a poor fit inside the carby body & the fuel ate away the Loctite & where it previously ran good,the hedge trimmer returned with running problems,I can tell by placing the carby inside a jar of water with the hose attached to the fuel supply & applied air pressure to the hose then found out that air was leaking from around the check valve.
I ordered another one for $30 AUD & it ran as good as gold.
I had to carefully isolate the problem because the caretaker who used that 2 stroke lawn equipment literally poured 2 stroke oil into the fuel tank without measuring it.
That's why a lot of the Stihl leaf blowers I repaired of theirs needed their spark arrestor screens cleaned as that caused them to Lack power.
I burned the carbon out of them with a propane torch,normally you shouldn't have to because Stihl recommends a 50:1 fuel to oil mixture which means that the exhaust is virtually smokeless !!!!
Thanks for this information, quite helpful. One comment, though, the crud on the screen is really not corrosion.
SPARK ARRESTOR!!!!
Why don't you know that?
In the Western third of the US, where conditions are generally much drier, the SPARK ARRESTOR is usually REQUIRED by forestry and conservation agencies. For most of us, spark arrestor maintenance is part of the program.
Basucally a good and useful video. Thank you.
I just bought an 87 homelite for $2 from the junk yard. Shot some carb cleaner though the intake and it fired 2nd pull. New carb rebuild, new magneto, new spark plug, half the bolts were loose, and it was just buried literally to the handle in the mud in a scrap pile. My guess is they had issues with it not running under WOT, tore it all apart and changed everything, then just gave up when they couldnt figure it out. Their loss, my gain. I got a practically free bright neon orange saw😂
When I'm done using my saw and I'm not going to use it for a while I always pour out the fuel and run it til it runs out of gas that way when I get ready to use it next time I can put in fresh fuel. Saves a lot of headaches later.
Thank you! I have spent way too many hours checking/cleaning the wrong spots!
jiminmontana 👍😁
Fantastic insights and a great video, Now my interpretation: gGet rid of the screen, put it in the garbage and reassemble and never worry about that again.
Bad idea, that screen stops sparks from exiting the saw. Clean and replace or just replace.
Depends on saw, exhaust screen, spark plug, good clean fuel, air filter clean, been sitting carb cleaning, inspection. Runs bit funky carb possibly, then adjusting like here...
Solved my problem on the same machine, thanks!
brilliant....you have solved my biggest headache..
+JOH KNEE Q glad it helped!!
That's a really organized workspace👌 definitly fits in a 5S program
Damm commies bringing in their organization techniques
I guess I just fixed mine by removing the muffler and cleaning the screen. I had tried the low/high speed adjustment and only when I did this did it start to work. Thanks.
the little holes before the spark arrestor screen is the part where I drilled bigger holes and where the little fins are on the exhaust ,I bent them out a little more, for better flow. And one more good tip is the combustion bowl would be so caked by looking at that screen. Take out the plug and spray that head cleaner or tune up in a can . put the plug back in and dont put the plug wire on it . pull it a couple times slowly and let it sit for awhile 30 min. approx. then take out the plug and spray some starter fluid on the plug Pt. put it back together and start it up and watch all these chunks of old hard carbon fly outta your muffler. Ive done this to so many motors that wont run well. Might have to clean the exhaust again because of all that crap might not make it out with the screen and small holes. Runs like just bought most of the time.
Thanks Pal, this makes a lot of sense. Will check my saw for same problem.
I always appreciate the "easy fix".
Thankyou. Similar problem on strimmer. Didnt know there was a gauze on muffler. Sorted my liw power, it is like a new one now. 👍
brian riding 👍😁
Over time that screen (spark arrestor) can rust apart and pieces could find their way into the cylinder. I blew a saw that way a few years ago. Chuck it. Thumbs up for the vid.
slofr8dan thank s for watching and sharing👍👍
good video but these saws have very poor carbs on them i remove them and put a fully adjustable carb on and the saw runs so much better more power and no bog but after installing the new carb you need to set the rpms on it to factory settings the old junk carb you just throw it away. the new carb is a Stihl carb costs $28 and it fits the 025 saw but will fit the 170-180 I have done hundreds of these swaps it turns the saw into a real saw
Stihl dealer is where you get the carb the part number is 1123-120-0605 and there is a couple things you need to do to it but its very easy first the pulse hole in this carb has 2 holes one is plugged you need to remove the small brass plug best way drill it then use a pick to pick it out next you will need to slot the butterfly rod out i use a cut off tool takes 10 seconds and your done the new carb just has a hole in it grind the slot in for the throttle rod then install carb just like the old one then you will need to put a litte rtv in the filter housing where the little round vent on the old carb went into air cleaner then put it together there are jet adjustment holes in air cleaner box already then you will need to drill a new hole in the handle for idle speed screw i just eye ball it then you will need to put a small slot in the housing so you can adjust the jets when the top cover is on very simple use a drill or cut off wheel then your done fire it up set the high and low speed jets now take it out and cut with it way more power and no more bogging down its very easy it takes me 5 min to do the whole job
+Sandy Wanous damn didnt they teach you in school to use a period at the end of a sentence?
+Sandy Wanous You should do a step by step video on that.. I think it's something that needs to be shown.. thanks for the comment!!
Sandy Wanous please send me the carb.number. in order to bye one for my stilh
You got some good tips and info...but I gotta say, your ability to construct sentences and use punctuation is more than archaic.
Good and useful advice, well presented, thanks.
When I was a teen my dad had a monster Lombard Comango which we would cut cords and cords of wood every year in Maine with, he never ever got a chance to show me how to tune it, just sharpen it!
Thank you ! My screen was plugged.
No More Bog !!
Had to do the same thing with my stihl leaf blower. Ended up just cutting the screen off altogether. It's ran great for 16 years now.
You are awesome thank you so much I went to mechanic school for a year and they never thought me that thank you!!!
Great explanation. You’re a wonderful teacher.
👍🙂
Hadn't thought about the ol' "potato in the exhaust " problem. I'm going out and inspect that screen now, Thanks.
👍😁
Video helped out. Going to try out chainsaw for the first time.
😊
I wish I was that smart. Nice diagnosis.
I throw those spark arrestor screens in the trash. nothing but trouble have fixed many saws and weed trimmers and leaf blowers with the same problem they run great after doing so. its funny how people think its fuel related a lot of times when its a plugged muffler screen or exhaust ports on a 2 cycle engine
So true
Hi Foxboss9, I just replaced the rotted off clunk/fuel line. Thought that would make her run. Nope, runs, but the top end dies out. I run 32:1 gas/oil mix, so your idea of the exhaust screen may be the problem, I will try that next. Gas is two weeks old.
I run 2 stroke "Chain saw engines" on my large radio control warbird aircraft, so have a fair amount of experience with these engines. I have run 32:1 to great success, for over 5 years. So, this poulan engine ran great 2 months ago. A couple of weeks ago, I tried it, and blah, hardly ran. Could be a combination of errors such as dirty fuel screen in the carb. Engine is 7 years old and has run great up till now.
Good luck
lbjlbj1 all stihl products run 50:1 period, youll end up frying the piston and cylinder and it will not take long. first sign is your gonna start loosing compression
curtis kitchens that is what Stihl recommends using their oil... Better mix oil such as Echo's ISO-LEG-D rated oil can be used at a lesser ratio. These guys aren't worried about warranties on their old saws. MFG recommendations are just that. For every saw that has burned up there are 20 doing fine. Just like no load full Rev.. Fuel limitation based on carb design will not allow a well tuned engine to scatter if it's wound up to it's upper limits.. For every one that has come apart there are 70 that don't experience I'll effects. Theoretical operation standards are rarely the actual abilities. I listened to all the Mfg's during all my training over the years and found that they all are teaching what is in the best for the MFG and never, ever what you can get away with. With the exception of Echo's advanced failure analysis class in which they have shown that you can run their cheapest string trimmer on straight gas, at full throttle for over an hour (refill on the fly) and will continue to run. It will be damaged but can be done. Showing that with a very minor amount or oil in the mix it will do the same thing without damage. But obviously they don't recommend it.
Why I like buying the premix out of the can good for 2 years. How often does a home owner cut wood . Shut off leave it until who knows when . 20.00 Gal it is worth it . Keeps it nice clean.
I just picked up 2 Echo CS340 and 440 at a recycle center just need to clean carb out.
A plugged spark arrestor is a common problem. My advice would be to just throw the thing away. Don't even try to clean it!! Another tip is to use non ethanol fuel with 2 ounces of sea foam per gallon of gas. Ethanol based fuel in time, will destroy a carburetor. Taking this advice, you will never have a fuel related problem again!!
+DR Dan there is an alcohol formulation in Seafoam. However, over 30 years, I personally never had, nor have I ever heard of any negative incident or effects of using Seafoam on any level with any engine (small or automotive). Using Seafoam as a cleaner or fuel additive(running/storage) will not harm components if used correctly (even incorrectly in some cases). The stuff just works.