Like I said earlier, Just bypass it like Affordable Go-karting shows how to do on there web site. If the motor is box stock why tear it down to get the governor out. Wait until you have the money to buy the rod, flywheel and valve springs to get more power out of the engine. Even with the current governor problem these engine make very good and reliable power, They start on the first pull usually if not second when 35 degrees out. They become addicting. And at the 75-100 bucks on sale they can be a cheap power in a bike your not wanting to be 100% correct, Just fast.
Restore Kid,
You need to break down and try a 6.5 Clone, You will be hooked. I did not think I would. These engines make for a relay nice cruising engines. I do not notice as much vibration as with the flathead engines when turning higher RPM's.