Help for a newbie

HI guys. I recently bought a 2003 wr450. I love it I have been riding it with the stock throttle stop for a while and just put in the yz throttle stop. The thing is insane now. It rips moe than my old xr650r. Will I notice a differance and what will I notice if i take out the air snorkle thing. Also, what will I notice if I cut the grey wire? One last thing. It seems to bog down when I try and accellerate quickly. How can I fix this? Thanks alot guys, Denis :)

Yes, open up the airbox, this will allow more air into the engine and increase performance.

Yes, cut the grey wire, this will change the timing curve in favor of increased performance.

The bogging is a jetting issue. There are many guys on this forum currently trying to figure out the perfect WR450 jetting. The carb. on the Wr450 is completely different from my Wr426, so, I cannot really help you. I suggest you do a search on jetting or look at the jetting q's and you will get a feel for what you should do. There have also been some recent posts on WR450 jetting. From the work that others have already done, you should be able to get close. :)

I assume you have pulled the exhaust baffle out? If so, do the other mods and re-jet. The WR is jetted from the factory for being all corked up. Unless you are at high elevations I would reccomend a 160 main and a 48 pilot to start with the stock needle.

Check out the post titled WR450 jetting Q's for more information.



When I picked up my bike, Ray (the guy at Yamaha) had already "uncorked" it, ground the throttle stop down, removed the air baffle T-looking thingy, and done something to the grey wire (which he explained was the rev limiter).

I had him put on a Pro Moto billet silencer because of my line of work. (I was in Georgia when he put the bike together) He liked it so much no bikes go out of his shop without one now.

That and jetting should rear the beautiful beasts head.

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