Stihl chainsaw stalling? Simple fix? Check if it's a clogged vent.

Sometimes it's not the carburetor, or bad crank seals. Sometimes it's a simple 15 minute fix! Symptoms were, starts okay, starts to lean out (idle races) after a couple minutes, then dies. Won't restart unless it sits for a while.

[scottreese]

Been running chainsaw 40yrs and never thought of that for the revelation.

[keithdrewv]

Thank you for this! I'm pretty good with engines and carbs, but this little vacuum valve had me going crazy, all good now!!!

[Gingerwhale]

I bought an used Stihl 025 model (16'' bar) about 15 years ago. For the first time this year I decided to have it checked-out at a repair shop because of this stalling problem. They replaced the coil and overhauled the carb ($$). Even after this the stalling continued. Your upload gave me hope in resolving this issue. On my model the air vent, possibly a homemade fix, is just a 2.5'' vertical plastic tube that has a small screw inserted at each end. Removed the screws and pushed air into the tube. Now the saw is running very smoothly again. Should have watched your video before going to the repair shop. Thank you so much for your great insight.

[robertwillis]

Thanks for the help! Turns out the tube was getting pinched by the carb.... so its got free flowing air :)

[markstack]

The new vent fixed my Stihl MS 290. Thanks very much. I was so frustrated after replacing the piston and cylinder that were really scored. It started and ran strong for a few minutes and died. It was a clogged tank vent. It now runs strong and long.

[Killuminatix]

That fuel starvation is real, I did what you did and just cracked open the gas cap. She’s running again, thx for your info

[stephenthomas]

I had the same problem, but with your help, I was able to reair😢 my ms310. Thank you. Great job.

[roadkill_]

I have a Stihl M250 with not many hours on it that was having this problem. Tried this trick, did not seem like it was clogged, but when I tried to start it again the thing came back to life immediately. Very simple thing to try first if having issues. Thank you !

[chriselliott]

Wow .... I've been struggling with this for a long time. Did a full replacement kit etc etc and still didn't work. So - thanks! Incidentally, I'm a bit lazy (or let's say I've got a trauma response to fruitless work!) so I took off the cover and see the little valve is sitting in a rubber cup. Thought I might be able to get it out, and off, without having to take the air filter off. I couldn't, but I saw a whole lot of dust and debris underneath so blasted it out with the air hose, then noticed the little holes were facing upwards so gave them a couple of blasts as well and - hey Presto! - it worked! Couldn't have done it without your good advice

[charlesemenaker]

Thank you, my 17 year old MS192T was having some issues. I would have not thought to check the fuel vent. After cleaning the vent, it works great now! Thank you

[dmorgan]

pondering throwing my ms250 to service...i've done all work on everything i own and didn't want to send off for repair so struggled with this issue for a while. I knew it was a fuel delivery issue, but carb was clean, filters good etc. runs good when not on vacuum. sure enough, this doodad was clogged. thanks for the video,

[fishtailfred]

That definitely helped, could not draw ait through the vent until I ran a tack through the side close to the fuel tank, Thank you.

[NormBeaulieu]

Thanks for the great video. This reflects the problem with my 250. I would not use a capacitor to clear out the check valve. If there is any charge on it, you could get a spark igniting the fuel.

[ninsnum]

Great! Thanks for this, I think it might be the remedy to my problem! I thought it was the ignition coil when hot causing issues but the leaning out and chain beginning to rotate until it starves is the same problem I have so I cannot wait to test this out! Cheers

[TicoTimeCR]

Just had the same root problem, but slightly different symptoms. The saw (MS250) would start fine, but idle was low/erratic. Full throttle would kill the engine. If left idling it would eventually die after about a minute. The fuel cap unscrewed with a slight suction pop.

Cleaned out the vent and it runs purrfect, and no suction on the fuel cap. Thanks!

[traviskassaiuli]

I’m so glad I came across this video! I live out on the Yukon delta, and this gets frustrating in the winter time! Thank you!

[sumtingwong]

Same system here. I tried this fix and it worked perfectly. Thanks for taking the time to post this video.

[OldDiogenese]

Thank you for the video. I thought there was a vacuum issue in the gas tank as I heard it suck in air when I took off the cap. Sure enough your fix worked. Many thanks.

[trevorjones]

Hi.
Just found your vid re breather, my ms181. Would not fire at all took the breathwr apart and hey presto works fine, after new carb and coil! Well done u.

[zone]

That is interesting! Mine after about 3 minutes leans out and then starts bogging really bad. I'll have to check that out. Thanks !!!!