Whats next? Performance mods

[kawirider]

Currently I have a Dr.D full system, Fastlap suspension revalve for both ends, (fastlap is a local co.), boyesen quickshot, and I am running good dunlops. What performance mods should I look at next. I know that there will be some of you that say "you cant use all the power as is" etc. etc. I just want to spend money on my bike to give me every possible advantage. So what should I get? It is a 2003 YZ450F. I dont want to spend any more than $500-$600

[YZ250F_Rider]

High compression piston, hot cams, head work, yz250 air cage and twin air backfire filter. And then some good suspension work so you can put the power to the ground.

Anyone that tells you that you cant use all of the power in any bike, has never won a race to the next corner and shut someone out of the better line thru it. They dont call it pinning it for nothing.

[dubious]

High compression piston, hot cams, head work, yz250 air cage and twin air backfire filter. And then some good suspension work so you can put the power to the ground.

Anyone that tells you that you cant use all of the power in any bike, has never won a race to the next corner and shut someone out of the better line thru it. They dont call it pinning it for nothing.

do the piston before the cams rather than cams then piston

that or both together is best.

the overlap from extended duration cams creates more cyl pressure blowdown, and reduces effective compression.

Thats why they always recomend high compression pistons WITH long duration cams.

That said a higher compression piston will give it more snap than the combined mods you have made already!

[kawirider]

Will I need to run race gas w/cams and piston or will 93 octane be sufficient? Also, I saw on the JE pistons website that I would need to deglaze my cylinder. Can anybody confirm that?

[grayracer513]

Most good 91 octane ( (R+M)/2 method) is adequate for 13.1 in most cases.

Any time you replace the rings you should run a ball hone through the cylinder. It's the single best way to be certain the rings will seat quickly and well.

[kawirider]

What kinda place do I take it to to get that done? (ball hone) About how much does it cost?

[scottbob99]

My 03 YZ450 has a FMF Factory 4.1 can and Powerbomb header and a JD jet kit and it runs awesome. I can consistently out run new '06's at Southwick. I'm doing a high compression piston over the winter, the shop said 93 octane is fine. Good luck.

[kawirider]

Yeah but how what compression ratio are you bumping it up to? Are you going to do 13:1 or 13.5:1? Also, will it be a lot harder to start now? I dont have a whole lot of trouble starting it but it still takes throwing all of my weight onto it a couple times. I imagine that it will be a little bit louder too.....

[kawirider]

cmon ya'll doesnt anybody run high compression pistons?

[YZ250F_Rider]

you wont notice it being harder to kick over enough to care.