MS 660 Chain Running at Idle

[Ayyy Lmaoooooo]

My 660 has been running at idle as of lately. I've adjusted the carb and can get it to stop spinning the chain at idle. It also tend to cut off when revving. I also replaced the clutch springs. I'm kinda at a loss for what is happening. One last thing is that it will ring slightly after stopping the saw/chain.

 

[cus_deluxe]

Is it running above normal idle rpm? Or is it spinning the chain at the reccommended idle speed?

 

[Ayyy Lmaoooooo]

Is it running above normal idle rpm? Or is it spinning the chain at the reccommended idle speed?

reccommended idle speed

 

[cus_deluxe]

Check ur clutch drum bearing.

 

[ZeroJunk]

Your clutch drum opening can get sloppy as well eventually and need to be replaced.

 

[Wood Doctor]

I believe you said this on the OP, "I've adjusted the carb and can get it to stop spinning the chain at idle." and you meant to say this, "I've adjusted the carb and cannot get it to stop spinning the chain at idle." Easy typo mistake to make.

Another possiblility besides the clutch bearing is a weak or broken clutch spring. That engages the centrifugal clutch at any low idle speed. I've replaced several of these through the years to solve the problem.

 

[2dogs]

I'm sure you know all this but for the chain to turn the clutch drum has to turn. The clutch drum is driven by the clutch shoes under normal conditions. The clutch expands as the RPM increases and grabs the inside of the drum tightly. I have had fibrous material such as string get wrapped around the crankshaft under the washer and cause the drum to turn at idle.

Scrape the inside of the drum clean and blow out the space behind the clutch. A little Simple Green before the compressed air helps loosen up the gunk. Better yet pull the clutch off and clean behind it.

Of course make sure the clutch springs are the right ones. Also the holes in the clutch shoes can elongate. This requires a new clutch.