064 not running right

[motolife313]

Had the same problem before taking it apart. Got a carb kit and it’s acting the same. I did notice the L screw was bent when putting it back together. It was going in wobbly. Hopefully that may be the issue. Right when I tap the gas it revs up to a much higher rpm and stays there, do you think it’s a good chance it the bent L screw?

 

[Dennisthemenace]

Need more details. Have you checked if the throttle butterfly returning to position when not triggering? That's a desirable saw, take it easy

 

[ZeroJunk]

I'll bet the bent idle screw has nothing to do with it.
Like he says, if your linkage isn't sticking, look for a crack in the intake boot and impulse line.
Make sure cylinder screws are tight.
If none of that check crank seals.

Don't run it that way.

 

[singinwoodwackr]

I've had 2 saws with bent screws Come in. Both showed air leaks in the carbs. One had your same symptom.

 

[northmanlogging]

air leak, somewhere, anywhere, a real good way to cook a saw
carb boot, and crank seals are the first culprits, usually the clutch side after that its a guessing game.
The bent screw isn't an issue (much anyway, could lead to tuning trouble but its not going to cause high reving)

 

[MartDalb]

that green gasket does not go on that side of the carb, picture nr. 2
It should be facing inwards towards the metal plate, that sits on the manifold.


You have the old version, like me, old style gasket, and larger metal plate that sits into the manifold rubber part.

Newer version uses a different manifold > small ring and no gasket because the rubber goes together with the carburator.

I can't say if that is the issue you have, but it could be, since you will have air going in without that gasket turning towards the metal plate/manifold side.

 

[stihltech]

Please Please do a vacuum and pressure test before proceeding. A saw with 30 or more years on it needs a bottom end verification. Air coming in past the carburetor cannot be regulated.

 

[MartDalb]

Please Please do a vacuum and pressure test before proceeding. A saw with 30 or more years on it needs a bottom end verification. Air coming in past the carburetor cannot be regulated.

I agree here.

Just pointing out the obvious thing from the picture here. Gasket sitting on the wrong end.

My 1988 model of 064 had a leak om clutch side, and both seals were hard and needed replacement for sure.

 

[MartDalb]

any update?

 

[muddy42]

I agree here.

Just pointing out the obvious thing from the picture here. Gasket sitting on the wrong end.

My 1988 model of 064 had a leak om clutch side, and both seals were hard and needed replacement for sure.

Agreed. A pressure/vac test is the mainstay of any diagnosis and repair. The only work I might do before this would be basic cheap stuff - replace fuel filter, plug, clean air filter, clean muffler and carb. Further than that you need to test - test the lines, carbs and then the cylinder case.