Let's torque clutches
- Thread starter Dan Forsh
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Lakeside53
Stihl Wrenching
Yes, It's important.... I have had a few bad experiences with clutches coming off... I've posted a few times on this so the prior info should still be available via search.
1) If hand tightening was enough, why would they be spec'ed at 20-60ft/lb(various models, Stihl)?
2) Why wouldn't anyone not do this? It only takes a few seconds...
Some guys just rev up the engine and slam on the brake. Sure it will tighten it (assuming a left thread model), but...
On most models the problem comes on de-acceleration when the motor winds down faster then the rotating clutch....
1) If hand tightening was enough, why would they be spec'ed at 20-60ft/lb(various models, Stihl)?
2) Why wouldn't anyone not do this? It only takes a few seconds...
Some guys just rev up the engine and slam on the brake. Sure it will tighten it (assuming a left thread model), but...
On most models the problem comes on de-acceleration when the motor winds down faster then the rotating clutch....
Freakingstang
Doctor Freakinstein
Lakeside53 said:
I saw this first hand with a members 999 after it was ported. It was in the high 14K range when he shut it off (no bar and chain, or bar/sproket cover). There were clutch parts all over the garage.....After the fact it was funny, but during the "heading for shelter mode", it wasn't so funny.
Dan Forsh
Addicted to ArboristSite
Okay, after re-reading my post I think I need to clarify, when I said hand tight, I didn't mean by hand, I meant with a socket and ratchet, just not by measured torque. 
I use one of those aluminium piston stops and I remember the post by someone who shattered a piston when using one before. I have got one of those Stihl plastic ones that you insert through the plug hole and trap in the exhaust port, but the last time I tried to torque a flywheel back on while using it, I sheared the end off the stop before the wrench clicked and the newly created projectile nealy took the end off my pinky,
I use one of those aluminium piston stops and I remember the post by someone who shattered a piston when using one before. I have got one of those Stihl plastic ones that you insert through the plug hole and trap in the exhaust port, but the last time I tried to torque a flywheel back on while using it, I sheared the end off the stop before the wrench clicked and the newly created projectile nealy took the end off my pinky,
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Lakeside53
Stihl Wrenching
oh, so you mean "good and tight". We'll that's better then "hand tighten".
Yes, I have your PM.. Maybe tomorrow... It will happen.
Two recent events: I had an 051 spew it's clutch all up my driveway (my fault, but heck, it was just a quick test..) - got everything back by trolling with bar magnet! Rbtree's 372 also... not my fault!! And then there are occasional customer saw that you don't notice they've been into...
Yes, I have your PM.. Maybe tomorrow... It will happen.
Two recent events: I had an 051 spew it's clutch all up my driveway (my fault, but heck, it was just a quick test..) - got everything back by trolling with bar magnet! Rbtree's 372 also... not my fault!! And then there are occasional customer saw that you don't notice they've been into...
Dan Forsh
Addicted to ArboristSite
Okay Andy, thanks.
I'll look up the torque setting and dust off my torque wrench, now as I've almost got all feeling and functionality back in my finger.
For anyone who can't visualize the event described, the muffler was off at the time.
I'll look up the torque setting and dust off my torque wrench, now as I've almost got all feeling and functionality back in my finger.
For anyone who can't visualize the event described, the muffler was off at the time.
Lakeside53
Stihl Wrenching
Dan Forsh said:
Ha!! Well.... that could be a long list.
Yesterday I put a flywheel back on an 034, but didn't notice it pushed out the flywheel key... Went on 45 degrees off when tightened. Damn near ripped my hand off! Got the key back though - stuck to the back of the magnets.
The clutch "coming off" problems are mainly with outboard clutches... the inboard clutch gets held in by the cir-clip on the end of the crank if it gets loose.
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NoDipNoMore
ArboristSite Member
Here in the MOTOR CITY, your referring to Technician Tight! Tighten till it strips and then back it off a half turn.
It is a good idea to remove your piston stopper and pull the starter rope out abit, reinstall stopper and then tighten. Depending on how your saws recoil is set up, your recoil will catch before your stop when you turn the engine backwards back into the stop to tighten the clutch and put unneeded strain on the recoil.
