My saw is pulling chain at idle and continues to spin after letting off of throttle, but ( here's the kicker), only after getting hot say at least half a tank ran through it. Sometimes it gets hard starting after that. It's an 8 month old ms311. 93 octane with stihl oil. I don't think is has anything to do with the idle screw. I out the brake on and it sounds normal, no strain it only does it hot My old one never did this. This one is a NIB replacement that the dealer gave me.
Just needd a little tuning. It's not uncommon for this type of thing to happen because of how the tank gets pressurized to pump the fuel to the carb. Take it back to the dealer and explain your issue, or learn to tune it and save $$$ in the long run.
Sounds like you need to adjust the L idle. When it's cold, it's real near engaging the centrifugal clutch. As it warms up, the springs loosen up just enough to engage the clutch/chain. First thing, adjust the low idle to get the RPM's a little lower. If it were an old saw, I'd consider replacing the springs in the clutch, but it sounds like a relatively new saw, so DEFINITELY get the RPM's down at idle.
I bet one of the clutch springs is broken. I lost one on my ms290 and it would act like this. Easy to check. Pop off the eclip and lift the clutch off to expose and check those springs.
close... Breechlock1 are you comfortable adjusting a the carb? If not check this out: Saw Carb Tuning If so make sure the saw is warmed up before you adjust the carb. Aka. don't try tuning it before it's acting up. Then follow all the great advice from Madsen and Mike.
I'm betting is an low mixture issue, possibly a slight adjustment on the idle screw too... I highly doubt the crank seals are leaking yet, might also wanna check the spark plug for tightness. Just try to rule out all the simple things before you go crazy. I'm betting is a simple fix.....
Are we outta warranty coverage on this thing? If not I'd be asking the dealer to look into it. Wouldn't hurt to twist the idle speed (not the carb adjustment!) back out a half-turn or so and see how it responds. If it doesn't cure it, something is wrong.
LA screw only slowed it down. I touched the L screw a fraction of a hair and it stopped. It's in warranty so I'll take it in. It's got 3-4 gallons through it. I think it was settling in. I took my original saw in to have the kill switch fixed and they didn't put the air filter back on. I ran about three tanks through it before I realized it and called them. They told me to bring it in and when I walked in he handed me a new power head before I got to the counter. My original had 15 gallons through it. I'm sure they'll take care if the issue if there is one.
Some saws/ carbs are more sensitive to weather changes than others. Re-tune for the heat/ humidity and cut wood