Ms661c any owner ever have this happen

[junglejohnny28]

Today I’m using my 661c on some 36” trees , out of the blue the saw jumps up to like 15-16k rpm’s and doesn’t wantvto drop to idle all the way . I shut saw off , restart seems a little more rev happy put it in wood cutting fine , then 16k rev up and not return to idle !! Any thought . I believe something with mtronic , any help is much appriciated .saw is like new . But has a few hours on it .

 

[singinwoodwackr]

Today I’m using my 661c on some 36” trees , out of the blue the saw jumps up to like 15-16k rpm’s and doesn’t wantvto drop to idle all the way . I shut saw off , restart seems a little more rev happy put it in wood cutting fine , then 16k rev up and not return to idle !! Any thought . I believe something with mtronic , any help is much appriciated .saw is like new . But has a few hours on it .

Out of gas? All saws reve up for a few seconds when the tank is about empty.
I doubt it got to 16k, however.

 

[blades]

Might be dirt, leaning it way out or a fuel line that's sucking a bit of air.

 

[GrizG]

Could be an air leak… might be best to have it tested for leaks before things are trashed.

 

[ballisticdoughnut]

Don’t run the saw again until you do a vacuum/pressure test. If your not able to do it yourself find someone who can or have a local saw shop do it. Pull the muffler and check the piston for scoring.

 

[junglejohnny28]

Nop

Out of gas? All saws reve up for a few seconds when the tank is about empty.
I doubt it got to 16k, however.

Nope 3/4 full

Don’t run the saw again until you do a vacuum/pressure test. If your not able to do it yourself find someone who can or have a local saw shop do it. Pull the muffler and check the piston for scoring.

piston not scored , will have vac test done

 

[muddy42]

If you know how to remove the carb, you could remove that first. Look behind it and there will be a rubber intake boot. Check it for cracks or holes. Check all of the lines (fuel line and impulse line) for Cracks aswell. You don’t necessarily need a pressure/vac test for this part - just inspect them, bend them about and even blow through the pipes with your mouth with a finger blocking the other end.

If this all looks good, then the crankcase area needs testing.

 

[singinwoodwackr]

Nop

Nope 3/4 full

piston not scored , will have vac test done

Has to be an air leak then.

 

[junglejohnny28]

If you know how to remove the carb, you could remove that first. Look behind it and there will be a rubber intake boot. Check it for cracks or holes. Check all of the lines (fuel line and impulse line) for Cracks aswell. You don’t necessarily need a pressure/vac test for this part - just inspect them, bend them about and even blow through the pipes with your mouth with a finger blocking the other end.

If this all looks good, then the crankcase area needs testing.

That what it was ty

 

[trains]

That what it was ty

Intake boot split, or impulse/ fuel line cracked ?

 

[chipper1]

I doubt it got to 16k,

Right, I had to look twice, yep stihl, no 16k .

 

[chipper1]

That what it was ty

Which one.

 

[Jza]

That what it was ty

That's good . Easy fix !

 

[yellowking86]

Where was the air leak?

 

[stihltech]

Yep, must be the Mtronic.
Still a saw. Same issues we have had forever. I am betting pulled off pulse hose. Pretty common.
Visual inspection is the first step. Many issues are fixed that way

 

[junglejohnny28]

Where was the air leak?

Yes I found small crack in boot , when I was using it must of started sucking air .

 

[junglejohnny28]

Which one.

Crack in boot

 

[junglejohnny28]

Where was the air leak?

Yes

 

[junglejohnny28]

Right, I had to look twice, yep stihl, no 16k .

Extremely high ,