My HV 4.5 in my G2R flipped on its lid constantly if I gave it full throttle with 13/70 gearing. I've since switched to 15/70 and switched the e-maxx tranny friction pegs to ball bearings and it's been perfect since. Still wheelies and fixed the lid problem with a Tekno wing.

Plenty of top speed and torque for me. I only bash and don't race. I don't see the purpose of having so much top end around here because our local bash and track sites have a lot of jumps.