Ok, I have a manco american challenger,2 seater fox go cart..It has the 5hp Subaru 126cc engine..My questions are,what mods can I do to make it faster??And what can i do to get it to stop better??(brakes suck!!)I just replaced the clutch with a Hilliards centrifugal clutch..(May do torque converter eventually)..My biggest complaint is this thing is wicked slow..Ive already adjusted everything to go fast as possible(gov screw)..I mean its a dog taking off and only goes about 18mph..I can reach around and grab linkage under fuel tank and it hauls the mail then..Any suggestions??? THANKS in advance...