Motor building questions

[Jared Coderre]

I do a little work on the side for buddies. One has a 2004 YFZ450.

He gave me a list of things he wants in the quad. His intent is to race at a local track that does a motorcross style of race for quads. I have not been there so forgive my description.

Getting to the list, he wants the following done.

1. YZF 450 crank ( I assume the dirtbike crank for faster revs?)
2. 13:1 Compression piston
3. Barnett racing clutch

My question is are these the right mods? or can someone suggest/recommend the best direction to go?

For clarity, the engine is stock (except for pipe and jet kit and air filter). It has nearly a full Elka front and rear suspension. The handling is all there just looking to improve the power output.

[K_Fulk]

1. Get a wr450 crank, flywheels are different on the yzf's

2.I like cp's pistons. Make sure you get a piston for a bike if your using the bike crank.

3.Stick with the stocker and bike springs or get a bike clutch with springs. Most after market clutch plates don't hold up. If you use the bike clutch the clutch arm will need moved back a tooth.

Cylinder most likely needs replated or replaced being an 04.

Check the valves, clean off the carbon, get new valve seals.

Get a new timing chain while your at it, there only $12 bucks.

[JR3]

make sure he knows with a 13:1 hes gonna have to run race gas. I ahd my motor built for mx. I have a wiseco 13.5 comp piston,hot cams, the 06 crank, hinson hub basket plate and 9 plate clutch kit and cover. and a couple other odds and ends runnin vpc12 and thing rips cant keep the front down

[TWILES]

The Flywheels on the WR and YFZ are the same. I think they are 30oz. The YZ is something like 14oz.