Hi everyone, I started to ride the tracks this year and I really, really enjoyed it. My problem is 4 fold, 1. My current bike needs valve adjustments constantly, so to fix this problem I am going to remove the gas cap and put a dependable bike under it .( Can you guess what color it is?) Problem fixed! 2. I am thinking about a Yamaha, but money is kind of tight, so I am thinking about getting an older YZ450f. Is the steel frame (05 and older) that big of a drawback. 3. I am a little concerned about a 4 spd.. I currently have a 5spd. and would like some feedback from those that have had real world experience. 4. I have never had a Yamaha, and I just started my research, so what problems do they have and what should I look out for. Thanks to all, this is a great site.