im in the process of turning my 1988 Yamaha blaster into a aggressive trail machine/ occasional XC race bike. I started with getting my suspension upgraded and it rides pretty nice now and I can hit the trails hard. I think I'm ready to upgrade my motor now. It's all stock with just a toomey exhaust. I'm running 13/36 gearing and I'm usually 2nd gear mostly in the trails. I think I want to change my exhaust and build a motor that has good low end and midrange power instead of top end. What would a good setup be? Will post pics of my blaster later on.