Chainsaw "bog" what to look for and how to fix

Quick repair tip on basic chainsaw problems

[@colebowman9610]

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.

[@bigassdude7856]

Cole B yu spent the day cleaning a carb.. don't quit yur day job

[@unisol2287]

Next time try to use carb cleaner and it should be OK

[@andrewgraziani5214]

How to start a chain saw?

[@jjjsmith2497]

"big ass puss" People like you dont quit their day Or night jobs.. They get fired!

[@atlas3863]

next time it clogs up chuck it in the trash that’s where they belong.

[@martinswiney2192]

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.

[@dsgilmore5403]

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!

[@billstevens8553]

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.

[@brianmiller9542]

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.

[@febsat]

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.

[@SurvivalRussia]

The mesh screen is a "Spark Arrest" preventing sparks from flying out the exhaust in a dry environment ;)

[@gregwatkins2596]

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!

[@Jim-lp6zf]

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.

[@militarychevy711]

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!

[@Wanous-hv7zo]

Military Chevy or running CHEAP MIX OIL. run full synthetic it wont plug up

[@zianian]

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.

[@vortexvid]

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!

[@21Pescatore]

Thank You!! My 15 year old son watched your video, and now the chain saw is working great!

[@Foxboss9]

That is great!

[@johnd942]

+Paul L: A 15 year old boy is too young to be handling a chain-saw.

[@stevetaritas1781]

All depends on how he grew up...IMO

[@bluelightguy1]

Lol did you grow up in a bubble? Or just i Citydiot @@johnd942

[@leehotspur9679]

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

[@jeffquinn5653]

Nice job. Had same issue. Chased other issues for hours before finding this cause. Thanks for sharing. Well done.

[@johnhtreble9165]

This is the best and most informative video I've seen in some time! Excellent work!

[@brucegordon917]

Thanks heaps, great video, straight to the point! Clogged screen is now clean and MS170 is going great again.

[@denniscompton5800]

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.

[@Hitswing808]

Brother you saved me $45 and taught me a new skill. Thank you 10 time over.

[@multirichard007]

Thanks for getting and keeping it to the point without wasting time showing me where the dog sleeps.

[@fixtritephil7712]

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.

[@jamesburk7385]

A great video have run saws for 40 years with Hydro and personal business. Thank you.

[@larryatkins5376]

Thanks for the concise video. I fixed my saw in minutes!

[@captain_kurbis3954]

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!!

[@Rottidog68]

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.

[@brucea550]

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.

[@Tuuktalus]

Thanks for the video. I just inherited my dads chainsaw and now I know a lot more about it.

[@Foxboss9]

Arian Smith 😊

[@jd-kd3mm]

Great video. Great info. Straight to the point and easy to follow. Great flow.

[@robertking7150]

My teenage years of cleaning my pipe and bong screens have prepared me for this exact task.

[@Foxboss9]

+Robert King And there it is..Best comment!!

[@Laffy1345]

Robert King LMFAO

[@anguskangus8222]

So, how much does it help ?

[@ZJhontu1]

Robert King hahahahaaa!!! IK-R?

[@johnrock241]

like a boss

[@joelee1972]

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.

[@Foxboss9]

✅😁

[@stephenzhang4131]

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.

[@dcolds5383]

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!!

[@nzbroker]

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.

[@thewalkingsketchbook]

You're a star, mate! Thanks. Exhaust was the problem. Shared knowledge is what makes the world go round. Thanks again.

[@Foxboss9]

great news! thanks for watching😀

[@keithridgway7606]

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!

[@klaymistic4810]

You are awesome thank you so much I went to mechanic school for a year and they never thought me that thank you!!!

[@c138599]

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.

[@Foxboss9]

;-)

[@colincourtney5990]

Good and useful advice, well presented, thanks.

[@propdoctor21564]

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

[@byronbrowne1732]

This video saved me. Thank you. Thank you.

[@burtvhulberthyhbn7583]

I always appreciate the "easy fix".

[@timtravasos2742]

I've never heard of checking the exhaust screen and muffler. Hmm. Good info. Thank you.

[@DJ..]

@Foxboss9 thankyou very much ! You just saved me a lot of money and 2 days sending my chainsaw to a service company. I guess you do learn something new everyday! Thankyou again.

[@jamiecox2506]

I'll be checking this tomorrow. Thanks for the tip!

[@davidfaller8033]

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!

[@joelboley2344]

Lol I've seen this problem on weed eaters alot! Never thought of it on a chainsaw! Thanks

[@hayhead92]

Thanks a million, I was almost ready to give up on my MS170 but this fixed it!

[@Foxboss9]

Great news!! Glad it Helped!

[@dabad7986]

Great video. Have the same saw it bogs down when I full throttle sometimes. If you do another it would be nice to see and hear how it fails before fixing.

[@davev5031]

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.

[@Foxboss9]

Dave V Great! 😊👍

[@MrNabkebab]

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 :)

[@Foxboss9]

Cool!

[@n124lp]

Thanks for sharing this tip. I would never have thought to check that screen.

[@Foxboss9]

n124lp 👍😁

[@jiminmontana]

Thank you! I have spent way too many hours checking/cleaning the wrong spots!

[@Foxboss9]

jiminmontana 👍😁

[@barryloftin4159]

Hey man I just had one give to me and I checked it and it was exactly like the one that you just fixed !!! Awesome thanks

[@tampabayrider]

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.

[@Foxboss9]

tampabayrider Great News 👍

[@billcallahan2830]

Great tip! I always go a tad heavier on oil. Only because very seldom does the saw idle more than 45 seconds. Other than warm up. It. Its wide open. I'm not a climber. Can understand that. From what I understand they have leaned everything out too. For epa junk. Spark arrestors a good idea. Never a fan of Sthil . Started with Mchulloch only because only descent service guy. 1010,610, and 710. All by age 16. East coast. Prefer Husky or jonsered. Lighter faster. Got a husky 40 brothers I bought my dad decades ago. Dad and one brother gone. Saw still here. 372xp. Saw does the work. Have to be on your toes. .what's your choice and why?

[@vince4578]

That's a really organized workspace👌 definitly fits in a 5S program

[@brandonstephens9890]

Damm commies bringing in their organization techniques

[@stronglikemonkey]

Very helpful! Thanks for sharing!

[@Foxboss9]

Thanks for watching..

[@mainiac4pats]

Bro, thanx so much, you are a great guy for putting this up. Amazingly helpful for me!! Two thumbs up!!

[@Foxboss9]

+Michael Fitzgerald Sure thing, glad it helped out

[@sfspencer1]

Thank you, very insightful.

[@benmarshall2996]

great video, fast and comprehensive. thanx

[@Otto-ub4ll]

My ms170 was bogging down. I was afraid it was a carb or compression problem. Searched the KZbin 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!

[@Foxboss9]

Otto 81494 Great! Glad it helped out!

[@JustinLukasavige]

Great explanation. You’re a wonderful teacher.

[@Foxboss9]

👍🙂

[@chicoleek]

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.

[@Foxboss9]

Thanks..good points for sure..

[@jeffjackson8381]

If you're spark arrestor is clogged like that, your mix is too oily, and exhaust port needs cleaning 🧐

[@WellStudied]

very helpful... never would have known it was there.

[@marpip01]

Pulled my spark screen out years ago also drilled out the holes in the muffler to let the exhaust out faster seems to have more power now but seems to have a little bit of a bog lateley and am wondering if the pump diaphram is getting stiff from the 110 low lead av gas that i am running .

[@alanrees4837]

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.

[@taterhead1234]

I was also having the issue of short idle and no rev. My saw has less than 2 hours of use. I checked everything like has been mentioned on several youtube videos and forums and all was fine, as it should be. It appears the in tank fuel filter keeps the tube off the bottom of the tank too high. I still had, what I thought was, plenty of fuel (about 1/4 to 1/3 full) but was having the run issues. I topped the tank back off and after it idled long enough to purge any air, it ran as it should. Hopes this helps.

[@cloudsandsea]

nice! quick and concise help for my 170

[@willloy8901]

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?

[@michaeltoth1]

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

[@anniversary4]

thank you for your quick response

[@6joenc]

Excellent video on a subject often overlooked!!

[@Foxboss9]

+6joenc 😃

[@imdowncow011]

And again great video this helped me a lot I had a similar problem on my snowblower

[@Foxboss9]

Those 2 stroke snowblower are still kicking around aren't they? I'll be glad when the 4 stroke blowers out number the older ones.i

[@PescadoAzure]

Love the soundtrack! Great video boss

[@InclinedTherapy]

Thanks Pal, this makes a lot of sense. Will check my saw for same problem.

[@jimdent351]

Maybe you can help me out. I have an MS 230 that has been acting up since new. When I bought it, I only used it for less than 1/2 an hour before completely draining the gas and put it in storage for a couple of years. When I pulled it out of storage I fueled it and started it up and worked fine for as long as I needed it. A few months later I went to use it again, and of course it started and ran well for 2 or 3 minutes but then stalls out. After stalling, when I start it up it runs rough, wont idle, and doesn't like going above a mid power RPM. If I leave it for a day or two at this point it will work fine again until I let it sit for a while. Any Ideas?

[@Foxxie55]

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)

[@Daniel_Antonio_Arellano782]

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.

[@Wanous-hv7zo]

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

[@ryanjames170]

i would think if it was throwing sparks it would be a good sigh of the saws engine starting to die.

[@kutzbill]

The sparks are carbon, not metal.

[@RonKris]

Good info! Thanks for your input. Experience will always win.

[@spelunkerd]

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.

[@philiprust2599]

Thanks for the really helpful video.

[@mrkokkinakis]

great vid! thx! but what is your advice when the same model isnt cutting as strong?

[@brianlauder9636]

Thanks Mate, that fixed my saw straight away.

[@outonthesun]

Great, helpful and quick. Thank you!

[@dragonfly1949]

Thankyou. Similar problem on strimmer. Didnt know there was a gauze on muffler. Sorted my liw power, it is like a new one now. 👍

[@Foxboss9]

brian riding 👍😁

[@michaelpukmel9175]

Thanks, awesome video!

[@Foxboss9]

😁

[@neilreid9005]

Thank you for this! I'll check my Husky for this issue. Everything else seems good but it still bogs a bit. Many thanks!

[@Foxboss9]

, 👍😊

[@artdewerk2192]

Thanks for the concise and understandable information!

[@Foxboss9]

👍😁

[@fergusonman7940]

Very helpful, Thankyou for sharing , May God Bless

[@rongraff790]

Thanks great video, thanks for sharing 🇺🇸

[@normanziegelmeyer7693]

I own an old 021. Last year I overhauled it including a new sprocket. I put it away without cutting anything. I tried it last weekend, It starts and runs fine, It cuts fine, it oils ok, but it seems like the chain stops easier than it should in a cut. It's been a couple of years since I did any cutting so I don't remember for sure how it used to be. Can you suggest any cause/fixes for this or if it's even a problem? Thanks

[@cartelli50]

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.

[@Foxboss9]

+cartelli50 great news!

[@michaellewis9599]

Solved my problem on the same machine, thanks!

[@meMiner]

Perfect. Too bad I didn't look under the muffler before trying to adjust the carb. I suspect I was heavy on the oil in the gas. Glad to have my little saw back.

[@sethcardwell5480]

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.

[@mst5632]

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.

[@charlesmiller7848]

He did that to a customer's saw. Unbelievable.

[@karlrovey]

You have to at least do a throttle squeeze on Stihl if it is on the half-choke.

[@blackwell2001]

Video helped out. Going to try out chainsaw for the first time.

[@Foxboss9]

😊

[@caduceus33]

Thanks for this information, quite helpful. One comment, though, the crud on the screen is really not corrosion.

[@Bob_Adkins]

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!

[@clementgeorge1246]

Might also check the impulse line for cracks. Replace it if cracked or it won't idle/spool up right.

[@paulanderson2464]

Great info... Dad always said it's the big three -air, fuel and spark ... Most fail to realize breathing = inhale AND exhale.

[@TheSimpleObserver]

Nice truck, I have a 1995 F250 in the same color. Thank you for a great video.

[@Foxboss9]

Thanks, make sure to check out my other videos covering stuff I've done on that truck.

[@alanrees4837]

do you know where the spark arrestor screen sits on a stilth 171 chain saw

[@spiderstone]

Thanks foxboss.....I found filter......appreciate the help......may have another coming soon.....thanks

[@ZJhontu1]

Thank you so much for sharing this. I’ve pretty much done everything EXCEPT check the exhaust. I bet anything that’s the problem. Only been an operator for two years so I’m still wet behind the ears when it comes to this tormenting wretch. But I’m going out there now and fix it... thanks to YOUR HELP. Stay warm!!! I know I can now!!!

[@Foxboss9]

ZJhontu1 👍😁