Stihl MS361

[joe_indi]

..........Flicking the throttle will get it to idle back down. Suspect what is causing the over-revving is also the culprit for the idle problem.

Usually this happens if the butterfly valve of the throttle has moved sideways from its original position.
Examine the carburetor to check that the valve closes down properly.
An increase of air need not necessarily mean that there is an air leak. An increase of air only alters the air:fuel ratio. It can be altered the same way if the fuel supply is reduced.
So check the fuel supply. Pickup body, fuel tube, tank vent, strainer, inlet metering lever, stiffness of metering diaphragm, jet valve (check valve), L screw setting.....
Additionally check the cylinder screws. If even one of them is slightly loose, I would lift the cylinder and check for a gasket leak.
Joe

[celliott]

Have an update on your MS361 Beenthere?

[beenthere]

celliot, thanks for asking.

Best update I can give at the moment;
I put a new boot on and that fixed the over-revving problem.
Couldn't find any leak or pinhole in the old boot, but must have been there somehow.

Now the only problem is setting the idle. Can get it to idle great for about 10 seconds and then the saw dies as if shutting the switch off. If able to flick the throttle, then it doesn't die. So seems to be a problem with the steady flow of fuel to the carb. 

So am planning to replace the impulse line, filter, etc.

Thanks for the input from several of you.

[celliott]

Alright, cool sounds like you fixed the air leak.
You said you're planning to replace the impulse line, filter, etc. Will "etc." include the fuel line as well? I would add a carburetor kit to the list while you're at it. Cheap and easy.

[Andyshine77]

Sounds like the saw is loading up with fuel at idle. Slowly turn the low speed needle clockwise until the saw speeds up and almost dies. Now back the needle out 1/4 of a turn, now check the throttle response. The saw should accelerate quickly without hesitation. If the saw hesitates, open up the low 1/8 to 1/4 of a turn. After the low speed screw is set, adjust the idle screw.

[beenthere]

Andre
Will give that a shot... thanks for the tip.