need some help figuring out a drivetrain
 

We have recently installed a 6.5hp clone engine with a cam, jetted carb. and pulse fuel pump, header pipe, and also ungoverned, so it runs around 13hp. The tires are 22in in the back. We are having trouble figuring out a good way to get the power to the wheels. We bought a centrifugal clutch which just burnt up after one use. We were looking into different types of clutches and couldn't figure out what would work best.