Replace the intake with a 2" UNI filter, rejet your carburetor and upgrade your CVT to 17g sliders and the red Malossi torque spring.

250's dont need to turn more than 8000-8500. ligther rollersor sliders will spool up the engine quicker. some cdi's will remove th rev limiter, but if you are not hitting it now then its a waste of money. and what Peter just said

Pricing on parts that you requested

1) gear kb005610400 $70
2) spline sleeve kb005611100 $22.16
3) seal kbkb005610300 $8.10
4) QTY. 2- gbt894.2 2x0.81
5) QTY. 2- kb005612700 2x0.81

A new tranny is $200

I will double check on these prices just to confirm.

Glade