Hi, I'm trying to find a new dirt bike to buy. I'm having a hard time trying to figure out which size and model I should buy. I do not plan on racing for 2-3 years so I would like a quieter 4-stroke rather then a 2-stroke built for racing. The other problem is that I am very small for my age (13) though. I'm only 5'1. My uncle who has been racing dirt bikes for 20 years reccomends me to get a 150 4-stroke because he says it will last me 4-5 years and if I ever decided to race it would be good too. I'm wondering if this is too big for me to start out on. I have never rode a dirt-bike before but my uncle will teach me and I know how to shift and all that stuff. So should I try and find a used 150 4-stroke or should I try to get a 125 4-stroke instead because its smaller and easier to start out with but the problem with that one is I might outgrow it soon and I dont plan on buying too many bikes in a few years. Please help me.