On Tue, 11 Dec 2007 20:13:03 -0800, "Calif Bill"
wrote:

Tension on the idler
pulley would sorta regulate the speed.

Only by allowing varying ammounts of belt slippage. You would get very
poor belt life. I have seen this kind of setup, My dad built a lawn
tractor with that kind of clutch. Had a transmission from the flap
mechanism on a B-17. It had only 3 horse or so.

Casady