385xp weird recoil issue

[wcorey]

Anyone ever had this happen?



A new one on me…

Built and ported a ratty old 385xp from a couple basket cases, sort of a last minute thing for the NY gtg.
Fired up no problem, tuned the low to get it idling, couple short piss revs and Bam!
Seizes up very abruptly, small bits of black plastic on the floor, recoil feels all funky.

WTF!?


Took off the recoil, plastic and rope fiber everywhere, can’t find anything obvious for a cause. Somehow something pulled the rope out from the center of the recoil spool.

The air conductor/shroud and induction duct are fragged, coil wire farked, rope obviously toast but no sign of what could have caused it. Flywheel pawls functioning correctly, no sign of any contact of anything foreign on the engagement area of the spool.

Fixed the plug wire, put on another rope and everything seemed ok.
Walked it out to the woods for the inaugural cut.
Started, a few piss revs, go in for the cut and it locks up again, this time not quite as nasty feeling. The rope was all twisted up but survived this time, yet again can’t find any obvious cause.

Put it back together, make a few cuts, it’s fine. Ran it all day at the gtg, still fine. Shrug...

I dunno, head scratcher…

 

[Daserlon]

I had a similar thing happen on a 50. The rewind spring wasnt wound tight enough to pull the rope in fast enough while starting it. The rope didnt wind back into the rotor but on the flywheel side of the rotor instead. If thats not it then maybe too long of rope filling up the rotor and allowing it to get down by the starter pawls.

 

[Chainsaw Jim]

The knot was too big and the pawls caught it. You need to make sure the knot stays recessed down in the cavity or it'll keep happening.

 

[67L36Driver]

The knot was too big and the pawls caught it. You need to make sure the knot stays recessed down in the cavity or it'll keep happening.

Had that happen on my second Farmertec 660 build. Tore the chit out of things.

 

[wcorey]

The knot was too big and the pawls caught it. You need to make sure the knot stays recessed down in the cavity or it'll keep happening.

Believe me, that's the first thing I looked at but these have a pretty deep cavity that the knot sits in and it's not very close to the pawls.
When I put the new rope on, the knot was a bit fat to fit in past the washer and I had to really push it down there hard and it was really wedged in.
Can't imagine how it got anywhere near the pawls...

 

[malk315]

Yikes. Hope she stays decent.

 

[Duce]

Chainsaw Jim has it right, seen that more than once. Make a tight small knot, remove screw and washer, set knot as deep and replace washer and screw. Saw a small twig get into recoil and do that also.

 

[wcorey]

Chainsaw Jim has it right, seen that more than once. Make a tight small knot, remove screw and washer, set knot as deep and replace washer and screw. Saw a small twig get into recoil and do that also.

Really? Sure your thinking about the same saw?
The knot would have to be huge to get anywhere near the pawls, it sits more than a half inch down in that cavity and the pawls are farther away still.
The washer wouldn't need to be removed because it doesn't overhang the shoulder it sits on.
The knot gets wedged in there pretty well just from pull starting.
I could see a foreign object maybe doing it somehow but unlikely twice in a row and with no apparent damage to the spool.

It didn't happen during starting, the rope was fully wound in and the saw was near open throttle both times.
Two different ropes, two different knots.
I can't envision how the knot would back itself out an inch under those circumstances.
The first time it happened was too much of a mess to discern much from it but the second time was everything was relatively unharmed and I just untwisted it and pulled it back through, been fine since.

 

[wcorey]

Just remembered I caught the second time on vid, was attempting to record the first cut..

 

[jacob j.]

It also happens if the rope rotor is really worn- so it's sloppy on the post of the recoil housing. It bounces around until something catches on the pawls.

 

[Duce]

Really? Sure your thinking about the same saw?
The knot would have to be huge to get anywhere near the pawls, it sits more than a half inch down in that cavity and the pawls are farther away still.
The washer wouldn't need to be removed because it doesn't overhang the shoulder it sits on.
The knot gets wedged in there pretty well just from pull starting.
I could see a foreign object maybe doing it somehow but unlikely twice in a row and with no apparent damage to the spool.

It didn't happen during starting, the rope was fully wound in and the saw was near open throttle both times.
Two different ropes, two different knots.
I can't envision how the knot would back itself out an inch under those circumstances.
The first time it happened was too much of a mess to discern much from it but the second time was everything was relatively unharmed and I just untwisted it and pulled it back through, been fine since.

View attachment 122048

Yep! Really!

 

[67L36Driver]

Happens on Stihls because the starter pulley ‘cups’ around the flywheel hub.

 

[wcorey]

Yep! Really!

Thanks, very concise, that clears it right up for me.
I always appreciate a detailed follow-up...