I'm a new rider and I'm trying to figure out which dirt bike to buy. I'm 21 years old and I'm 5'7 and I weigh 140lbs. I want to stick with Yamaha bikes if I can. My budget is more or less $2K and that's the hard part. I found a TTR 125 and a TTR 225 both for $1,800. I'm wondering if either of these would be a good bike for me. What are the differences between the two? Is one better for a beginner? I am also thinking about getting a 2 stroke bike instead but not sure of the pros and cons of a 2 stroke versus a 4 stroke?