Anyone know of any mods avialable for an Eton 40? My son is 4 and has it pegged all the way around the track at races. He raced this past Sunday and got 3rd as he lost to a couple of well modified 90's. He is beating other kids on 90's because he rides well.....but I am not sure what else I can do to give him anymore speed. Anyone have any suggestions? Thanks!