Review on High Performance Go Kart/Cart Forward Reverse Gear Box - Compatible with 2-11 HP Engine Motors - 35, 40, 41 Series by Darryl Buck

This setup requires considerable mechanical skill. The input shaft was .630, so it needs a little modification to make anything work. One bracket was included, the second would save a lot of work. With 20 ft/lb input I'm probably pushing the limits of survival, but so far so good. I started with a good quality synthetic gear lube hoping that would help. Update - After 18 months of occasional abuse, he's still alive. Impressed with the durability.