need some motor help

[TRX520RIDER]

can any one leave some posts on what i could do to my trx 2005 450r motor to get more speed what size sprocket to run what to set my jets at with the hrc powerup kit and a sparks racing pipe what size piston to run what kinda of valves please help and what would be a better air filter k&n or UNI thank you

[450rXtreme]

Speed is a relevent term you mean take off, top end, or midrange? All depends on what kind of riding you are doing. A Uni filter , 13 tooth front sprocket, and around 145ish main jet size (dealer jets not Dynos sizes) would compliment your HRC kit and should set you on the right track for quicker out the hole times and midrange but sacrificing some top end. Adding a revbox would make the topend loss not as noticeable by giving your engine 1,000 more rpms on the motors topend. Hope this helps ya alittle.

[the Z Man]

On my 04 I ran a 50 pilot and 200 main with stock air filter, open airbox.

I also had a GT Thunder pipe, 13 front sprocket and stock rear..