CRF 250 Kits Stage 1 Includes: Carb mod rejetted bog free and easier starting (does not include rebuild parts) TLR Valve springs Recondition head(clean, inspect and recut valve seats) Head gasket and valve guide seals Hi flow cut exhuast valves OEM intake valves Stage 2 (pump gas) Includes 1 plus: Porting NGK Race Plug (for quicker starting and better throttle response) Stage 3(race gas only) Includes 1-2 plus: TLR intake valves Hi comp piston 13.6(Wiseco) Hone and lap cylinder (cleaned and preped) Base gasket Stage 4(race gas only) Includes 1-2-3 plus: TLR race piston 14.0 (Wiseco) TLR billit cam Install seats with (Hi flow valve seat cutting) NOTE: To maintain proper performance the most over looked part is the cam chain. When ever you do a top end it would be wise to change the cam chain.