Was that Craftsman supposed to be a racer or just a little mud toy? I know the title on this thread says offroad, but I want it to go at least between 30 and 35 mph.
The craftsman topped out at 47mph
But to go off road and play in the mud I slowed it down. It's more fun the play in the mud and ride in the woods than it is to go to fast.
You need to understand that the faster you make it the slower it will take off
So if you want to play in the dirt do donuts ride wheelies then keep your pulley to a 8 or 6 inch.
If you just want to go as fast as you can down a dirt road then go with a 10 inch.
I think the first thing you should do is put a gas pedal on it so you can control your speed.
I use a brake lever off a bike connect it right to the governor so you can get max RPMs play with it a while like that then go with a bigger pulley
(( racing is the only sport that you need two balls ))