Stihl 025 slowly dies at idle

[Gagliano7]

I have a stihl 025 that slowly dies at idle and is almost impossible to start hot. I just realized the gas vent is missing would that cause a problem?

 

[BigChopper]

I have a stihl 025 that slowly dies at idle and is almost impossible to start hot. I just realized the gas vent is missing would that cause a problem?

Does the cap hiss when you undo it after trying to start it?

 

[hotshot]

I have a stihl 025 that slowly dies at idle and is almost impossible to start hot. I just realized the gas vent is missing would that cause a problem?

No problem w/ idling & a missing tank vent, but likely the carb’s metering diaphragm is old and too stiff & it just needs a new carb kit installed.

Assuming you have fresh gas & can’t adjust the carb’s low mixture L screw & the idle speed T screw to get a consistent idle, then clean it & put a new kit in it. Pressure test it at 8# before you put it back on…should hold pressure all day long.

I’d first pull off the muffler & make sure the piston isn’t all scored up!

 

[Wood Doctor]

I have a stihl 025 that slowly dies at idle and is almost impossible to start hot. I just realized the gas vent is missing would that cause a problem?

It likely could. I have replaced lots of tank vents and solved many problems in addition to yours. If that tank vent is missing, the engine may act like it has run out of fuel and die.

 

[Gagliano7]

I was able to adjust the low and idle. Had right at recommended idle RPM. It runs flawless at wot. If I put it down after about 15 seconds it starts to die. I blip throttle and it goes back to idle than slowly dies until I blip throttle. Also when cold it doesn’t die at idle only when hot.

 

[Gagliano7]

Does the cap hiss when you undo it after trying to start it?

Never tried that. I will check.

 

[2StrokeFondler]

Does it get better when you lean out your L a bit?

 

[Gagliano7]

Does it get better when you lean out your L a bit?

I couldn’t get it started after it was hot yesterday. I was going to try that. I just ordered a vent and fuel filter so when they come in the middle of the week I will try.

 

[stihltech]

Just let it idle and run and see how much fuel comes out the open vent. Most I have worked on will vibrate a LOT of fuel out which is then getting sucked in the air box, filter and carburetor. Replace the vent first.

 

[Vintage Engine Repairs]

Try leaning the L screw out.