Welcome to the sight, the stock lifans do leave much to be desired but if they run good, as good as one will a ProMod jackshaft kit will give you the torque to take off and maintain the speed! Honestly a 6.5 conversion is a little much for a 13yo 130# young man, I am 44 and weigh 200+ and my DB with stock trim gov. included is fast for a minibike! Be careful if you decide on a swap, the minibike feels no pain!