I have a 2000 RM 125. My son has started riding it around some. My concern is that he is just a little small and inexperienced for this bike. Is there anyway to tone the bike down a little? I don't know if it is even possible to do that, but my other option is to trade down for an 85cc bike. My son is about 5'6 123 lbs and 13 yrs old, any recomendations. Thanks in advance.