05 WR450 - overheating and other questions

Hi All -

I'm brand new to dirt biking (got to hang up the street tires when the baby was born :D ).

Anyway, my buddy and I bought two 05's over Memorial Day and have been ripping around getting used to the dirt. We're completely addicted and having a blast. Being in the NW there's a LOT of mud and ruts and steep single track riding. Needless to say we're riding pretty slow as we get our legs underneath us, and have been having our bikes overheat a lot on these steep muddy trails.

Any ideas what we can do (besides ride faster - we're working on that one :)) to keep the bikes cooler?

Also - The links I've seen to the uncorking mod all point to an older WR250. When we got into our exhaust pipes the piece we pulled out was shaped a lot different then the photos in the ThumperFaq link. Does anyone have updated instructions for the '05 WR450?

Thanks - looking forward to learning a lot from you all. :)

You can run additives to your coolant to help with overheating. I use a product from Redline called water wetter. Not really sure how well it works, but I have never overheated. :)


As far as uncorking your bike, you can remove the entire baffle or drill out the smaller baffle that is held in by rivets. I removed the entire thing and ran

for a while like that but ended up buying the Pro Moto Billet baffle. I like this best. More power and a little quieter. Also, remove the air box baffle as well.

This will give you about 1/3 more flow, then rejet to compensate and find out

what this bike can really do. :)

Proper jetting: 48 pilot, 1.5 turns on the fuel screw, JD red needle in clip #4 and a 165 main jet is where you should start for a cooler running engine.


Evans NPG-R coolant

First do all the free mods. Check the June 05 issue of DirtRider for an updated report of free-mods with pics (done on an '04).

I also jetted my bike with a 165 main and 48 pilot and a Zipty fuel screw. To address my overheating problems I changed the coolant to Engine Ice http://www.engineice.cc/products.html. Since I switched to this stuff, I've only had one instance where my rads started bubbling.

I also dropped a tooth on the countershaft sprocket to 13. Now I can use 2nd gear!! :)

*note* editied for typo's, I installed a 48 pilot, not a 46.

Thanks Johhny34 - I'll check out the link. I like the idea of dropping a tooth; I'd like to get into 2nd occasionally too!

Thanks for the advice - I'll check out the water wetter.

We pulled out out the entire baffle but I wanted to make sure it was OK to run it without anything in there. I like the low end power and extra torque, but if it gets better with the Pro Moto Billet I'll track one down!

Do you know where to find out how to remove the air box baffle, or is that a stupid question :) ? Maybe it's listed in the article that is mentioned in Johnny34's reply.

Thanks again!

Thanks Indy - I'll have to save the re-jet until I've got somebody to show me how, but I'm glad to have the settings. First I have to learn, uh, the basics - like changing oil :)

re jet before opening up any more flow. Get a manual and you will see where all the jets are. Once in the carb, it's easy. good luck

Like others have said, the bikes are running hot because they are running lean. Richen them up a little and they will run cooler. Since you are putting around, obviously the pilot circuit is lean. While waiting to rejet, at least, turn out the fuel screw on the carb, up to one full turn should help. :)

Thanks Indy - I'll have to save the re-jet until I've got somebody to show me how, but I'm glad to have the settings. First I have to learn, uh, the basics - like changing oil :)

You can go to the Sudco web site and see a detailed blow apart drawing of our FCR carb. First time you rejet you should pull the carb off of the bike and do all the jets at once.


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