Stihl clutches on long reach machines

[Perkins]

I'm having a nightmare with these clutches, on both the polesaw and the long reach hedgecutter. They cease up constantly, making it nearly impossible to start the machine, because the power generated on tickover isn't enough to run the chain/hedgecutter. The only way to start it is to go for full throttle, and keep the revs up all the time. As soon as you throttle off, the machine stalls.

 

The design of the clutch is poor IMO. The bolts that hold the clutch 'shoes' onto the machine cause so much friction that the shoes don't return to their central position when the revs drop. The spring isn't strong enough to overcome the friction.

 

I've tried re-building the clutch with the bolts slightly less tight, but they just come undone and then jam the clutch anyway.

 

Anybody else had this problem?

[Rich2484]

have you replaced the springs at all?

 

a worn spring will not hold the clutch shoes back on tickoer.

 

used a lot of long reach cutters and only problem was when the springs had worn, new springs and was always good.

[Ray1]

I take it your talking 4 mix machines? Try a little grease on the clutch shoe mounting boss.

[Perkins]

Yes both are 4 mix engines.

 

There's just one spring pulling the two shoes together, and it's not an old machine. I'll try a new spring tomorrow, but am not hopeful.

 

When I dismantle the clutch, as the retaining bolts are loosened, the shoes spring back to the middle, which is what they're not doing on tickover.

 

I've tried grease, WD40, oil, everything. It's just a **** design. The retaining bolts press the shoes onto the mounting so hard, that they can't pivot.

[GardenKit]

Yes both are 4 mix engines.

 

It's just a **** design.

 

I agree entirely. Its not uncommon on many makes, but more so on Stihl.

 

You can mess around with emery cloth, wd, grease etc, but probably have little improvement.

 

Replace the shoes, spring and pivot.

[Perkins]

If the shoes had bearings or shims, or were mounted using nylocks onto partially threaded bolts, that would work, or using set screws instead of long fully threaded bolts.

 

Thanks for confirmation anyway, it made me feel better somehow, that somebody else had the same problem.

 

Pretty surprised though, it's like nailing a catherine-wheel tight onto a post and expecting it to spin.

[GardenKit]

I think the shoes have a bush in their pivot end which seizes in the shoe. I have in the past pushed these out, cleaned them up and refitted them with a little grease. The bolt holds the bush, the shoe pivots around it.