How I'm building my prototype racer
1. Going Faster
5" engine drive pulley/centrifical clutch belted to 8" reverse pulley
1990 2.5 HP military surplus Deco Grand (Continental) 3600 RPM
We clocked this setup at 7 MPH, 16" wheels/ag tires will increase 1/3
clutch pulley belt wired to tractor frame acts as a disc brake
reverse hub w/two pawls locked were used, so wheel doesn't ratchet forward
a spring was added to the throttle so that the motor slows to idle if you loose control.