Stihl 064 "jerk" when starting

[CausticUC]

However that is an active kickback from early or very late ignition, I've had that on engines.

In this case that is not what is described, just that it stops until forced over.

I also fail to see how a passive electric device can cause a physical event like a compression blockage.

 

[drf255]

Had a ported 064 that did the same thing. So bad, I didn’t speak to it for months.

Messed up part was that it was intermittent. Ran like a Bastid though.

Coil mismatch to the flywheel.

Don’t care how big and bad you are, a coil firing too early will hurt you.

Like Harley said, if you have the shorty pull rope, you’re getting a smaller gear in effect. It will limit the force applied to the flywheel and make it occur more often. It’s harder to get the inertia.

 

[WidowMaker_1]

A coil gone/going bad will have the same effect

 

[WidowMaker_1]

 

[Totembear]

Until we get pics or the OP has his man check the things out we've suggested, we're just pissin in the wind with this one. @HarleyT , yeah, he said it got worse over time. Caustic thinks its a compression problem, I think its a mismatched coil/flywheel. Wont know til OP has both checked out.

 

[smcgarrity]

working on it guys...stay tuned

 

[Chainsaw Jim]

I fixed the same problem with an 064 last month. It was pulling over and firing just fine one day and then it went to destroying tendons in my hand. Still running good, but then it went the other way and starting firing so late that it started going pahpahpah at full throttle.
I replaced both the coil and flywheel and it hasn't had a problem since. It was a double key flywheel that I removed.

 

[smcgarrity]

I fixed the same problem with an 064 last month. It was pulling over and firing just fine one day and then it went to destroying tendons in my hand. Still running good, but then it went the other way and starting firing so late that it started going pahpahpah at full throttle.
I replaced both the coil and flywheel and it hasn't had a problem since. It was a double key flywheel that I removed.

This one is single key.

So as someone else pointed out, maybe previous owner put an unlimited ignition coil on it and it ain’t jiving! I’m hoping it’s that straightforward.

Would like to have someone do some performance mods on it after I get her back. Looking for recommendations!


Sent from my iPhone using Tapatalk

 

[Totembear]

Heres the link to @Definitive Dave research:
https://www.arboristsite.com/community/threads/064-066-ms660-18-flywheels-7-coils.282162/