hi As I found it hard to find the right information to set up my sons Generic Race GT I thought it best to give others a little help. What I have done: Technigas Next-R exhaust with manifold restrictor removed (ground out) Naraku 70cc big bore kit 19mm PHBG race carb with 87 main jet modified cable entry for the seat box with a stage 6 manual choke kit. 5.0 gram rollers Race air filter Race cdi unit Race reed block with Kevlar reeds Kevlar drive belt All this now gives a top speed of 50 mph on the flat with a 13 stone dad riding it and about 45mph going up hill I hope this helps.