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Centrifugal clutches

Posted: Mon May 15, 2017 6:11 am
by Jack Gifford
I bought a little centrifugal clutch for an offroad kart I built. I was surprised that it is merely steel-on-steel (sheet steel drum, cast-appearing shoes), rather than employing some sort of lining material. It worked okay for awhile but then started dragging at idle. I found both the drum and shoes are galled- which doesn't surprise me much. Any comments? Did go-karts get away with such a design? Or were "lined" clutches common?

Re: Centrifugal clutches

Posted: Wed May 17, 2017 12:56 pm
by Grouty
Not sure about the little go-carts, but I have a couple of Husqvarna Automatic's. Mine are the older type with bronze shoes in steel drums. No issues, so long as they are kept lubricated. The later ones used a steel drum with cast steel shoes. Again the secret to stop them galling was lubrication. I still use the oil recommended by Husky at the time .... Mobil HVI26
The gearbox outside casing temperature is up around 200 deg C after a day's enduro !!

Re: Centrifugal clutches

Posted: Wed May 17, 2017 11:14 pm
by minetymenace
For crying out loud, put a torque converter on it and be done :roll:


Re: Centrifugal clutches

Posted: Thu May 18, 2017 5:19 am
by Jack Gifford
I can't picture lube doing any "good", as my clutch is wide open to entry of dust and dirt. Seems to me lube would simply retain more abrasive dirt where it's not wanted.

I sanded the cast shoe surfaces and machined the drum ID smooth and maybe .020" - .030" oversize (it had very little clearance "at rest" before). It's now fine at idle, but haven't taken it out and run it yet.