Before I start let me begin with that I have 3 GPX4's that come with .12 HYPER engines. They all suffered from carb issues, which I have read on other threads here that other people have been fustrated with also. I first read one of Benny's post where he had the same problem and fixed it by changing to a nova carb. He seemed to have alot of experiance with this motor. I was able to get a mega carb from a friend and the motor ran much more consistant, especially when the temps got around 200F. I then became aware of his motor service and sent him one of my engines. Since the weather was nice today, I tried out the modded motor. For an rtr this motor was no weakling before I sent it to Benny. To be fair I drove the car with a stock motor and then swapped it out with the modded motor. Big difference everywhere. Biggest improvement was more snap off of the line followed by more HP everywhere. I am completely happy with the work that Benny did and would recomend him to fellow racers.