Went with the 79cc engine....Kids ride it too. Goes pretty well at top speed but sucks out of the gate. Gonna try a 72 tooth sprocket on the rear. Don't want to take the governor off due to the fact that the kids will blow it up! This thing is a blast to ride! Note to all who buy Predator engines from HF. Make sure the carb studs are tight before you fill the tank with gas. What a mess!!!