Hi,

I have a yz250f 06 model and I was wondering what I can do to make it go fast??

U mean faster haha there already pretty quick,
Well there's a number of mods to start with:
- Exhaust
- sprockets
- oversize piston
- gear ratio's
- reeds/valves
Etc

There is a lot of things you can do on your bike to customise it. What's your budget?

High compression piston, Porting, Expansion Chamber, suited to needs. Find one tuned to match riding in the power curve. Sprockets, and Carburetion. When ever building to go fast, Don't forget the brakes. Even though it sounds like you won't be stopping much.

How about just sell it and buy a 450 :-)