Our stainless steel Y pipe alone makes a huge gain in power especially in the mid range which is what you want for off trail riding anyway. We gained 7 hp and 4 lb feet of torque in the mid range. 3-5 peak hp with a broader powerband. Plus its only 149 bucks.
Next I would suggest the boyesen rage cage reed valves. The ProCool Billet head gives that motor some quicker throttle response and low end grunt as well. A 2.5 degree timing key is a simple 2-3 hp for only 15 bucks.
Our Back Country Pro Shift clutch kit is designed for low elevation long track models. It will definitely take more clutch weight with the extra power and when you free up the secondary with the torsion spring. Our weights in the clutch kit are adjustable from 68-80 grams each, so plenty of weight to add for the added power.
The stock pipe is pretty darn good on that model. Then I would use a Slp muffler though.
We also have a lot of lightweight components for that model. Drop a lot of weight with our chrome moly front end and rear suspension arms, lightweight brake rotor and track shaft.
http://www.bd-xtreme.com/index.php?..._shop=1&id_employee=3&theme=&theme_font=font7
