HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
kawirider

Whats next? Performance mods

10 posts in this topic

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

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites
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! :mad:

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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. :mad: I'm doing a high compression piston over the winter, the shop said 93 octane is fine. Good luck.

Share this post


Link to post
Share on other sites

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.....

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0