what to do to improve......wr 450

10 replies to this topic
  • aze

Posted March 13, 2003 - 02:14 AM


I ordered a WR450F for endurance beachracing.
I did that because of the benefits in cooling capacity, gearbox, e-start,bigger fuel tank.
My suspension got to be revalved/new springs anyway.
My question now is how to get my engine at the YZ450F level???
Are there any dyno results available of a standard/prepared WR?
Wich are the major differences between wr and yz engine?
What with the jetting specifications?
A lot of questions, i know, but after reading a few posts here i become to be afraid that i made the wrong decision on how easy it was to transform wr into yz horsepower!!!

  • Indy_WR450

Posted March 13, 2003 - 07:47 AM


Search this forum for mods in the last 2 months. Most are easy to find.

  • aze

Posted March 13, 2003 - 09:38 AM


Indy, i did, and i find a few things, but still confused about cams and jetting.
What is the exact difference between yz and wr exhaust cam?
Are the inlet cams the same?
What are the differences in jetting?
When i use a motocross pipe do i have to change the airfilter more than just remove the snorkel and baffle?

  • Indy_WR450

Posted March 13, 2003 - 04:00 PM


Hi Aze,

The following mods are pretty easy:
Air box snorkel removed.
Replace the muffler with one of your choice for noise since the European corks are welded on.
Rejet your carb with a standard YZ needle and appropriate jets. This part can be confusing since there are a lot of jets but you can ask racers in your area what jetting they are running. Get a Zip-Ty fuel mixture screw. Dont worry about YZ timing. Ride and have fun!

  • aze

Posted March 14, 2003 - 12:13 AM


thanks indy,
i'll keep you informed.
I'm planning to do a dyno test completely standard (euro specs) and then one with the modifications.
The exhaust will be a complete akrapoviç system
looks nnnnice, and look at the chart!!!

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  • Indy_WR450

Posted March 14, 2003 - 02:21 AM


That exhaust system looks good. If you want more peak horsepower and you are going to buy this system you will need the YZ450 exhaust cam. It should give you 5 extra hp with the cam. You will loose some bottom end but not to bad. Let us know how it goes.

  • aze

Posted March 14, 2003 - 11:03 AM


Indy,the exhaust system arrived today!!
For the long straits in beachracing i need maximum peakpower, so the exhaust cam is on my order book.
Now waiting for the the bike to arrive.
This is usefull info, thank you!!

  • Indy_WR450

Posted March 14, 2003 - 02:19 PM


Let us know when you got it all together. I am waiting to get an exhaust system after seeing what works for most of the TT members. :)

  • John_Lorenz

Posted March 15, 2003 - 07:06 AM


Pick up this months motocrossaction mag. It has a real good article in converting the WR to a YZ spec mx bike. Keeping in mind you want the lights and all as a wr the engine mods and setup may help you out here.

  • Indy_WR450

Posted March 15, 2003 - 07:12 AM


Thanks EGO. I have been meaning to pick up that issue. Sounds like a good article.

  • aze

Posted March 17, 2003 - 02:33 AM


Thanks ego.
We dont have mxa over here before next week.
Then i'm gonna buy it.
Is the article worth the money???


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