[Christ]

RE: Clutch - Visit a Tractor Supply Co. store, they have centrifugal clutches. If you just want somthing simple to drive, that will do it, and they have them for like $30 that can handle 10 HP, IIRC.

You could use the governor, but engine speed control is much more likely to get you a desirable result. If you have enough gears, of course, or a CVT pulley, that will net you better results than even a throttle control would, as you could run CVT into a normal gearbox, which gives you basically Infinitely Variable ratios. (IVT).

If you don't mind using belts, and you are any good at fabrication, you can make a CVT pulley with V-belts and pulley cogs. If you want to see one, go to any place that sells MTD tractor parts, and ask them for a "transmission pulley" or CVT pulley. They call it both.

It's a double cone that slides in the middle of a wide standard pulley, which changes the open diameter on either side of the double cone. If one side is input, and the other is output, you have variable drive ratios. It's a simple "hydrostatic" transmission setup that MTD and Craftsman used to use, and may still be using.