WR450 How to check for power loss?

9 replies to this topic
  • mcpga

Posted August 31, 2011 - 01:50 PM


I recently bought a used 03 WR450, it's very clean and all stock except for a FMF power bomb header and a dual sport kit, as far as I know. I bought the bike cheap from a guy who took the bike on trade and I was able to get the bike tagged easily here in VA.

I've put about 40 hours on the bike, it seems to run great, starts easily, the oil looks new after 8 hours of riding, it doesn't smoke and it doesn't have any leaks anywhere. The only thing I don't like is that it backfires on decel.

Here is my question: I keep hearing about what a brute these bikes are yet mine seems pretty tame compared to the 03 CRF450r I had. I could barley keep the front wheel down on my CRF, but my WR450 doesn't pull nearly as hard. I can't believe a CRF450 is that much faster, or is it? I'm thinking there is something wrong with my WR, but it seems to runs great.

Also, I'm not sure if the grey wire and throttle stop mods have been done, but the pipe is uncorked...Please educate me! Thanks.

  • ArcticWR400

Posted August 31, 2011 - 03:54 PM


Read the stickies about the free mods. Airbox, grey wire (if applicable on '03) uncork exhaust, YZ timing (or YZ cams... not sure which you need for '03) jetting and BAM!!! The blue dragon is unleased. Right now he's chained to the floor...

To give you an idea, I have a '99 WR400F and it will wheelie in 4th with a pull, and will power wheelie in 3rd even without me pulling or leaning back...

If you're still disappointed with the power output, THEN start looking for problems. They are very restricted stock. Even with the header, the stock silencer = no good for power.

Edited by ArcticWR400, August 31, 2011 - 04:10 PM.

  • strtdsmallproject

Posted August 31, 2011 - 05:20 PM


If your comparing a crf450R then u are comparing a mx race ready bike that hits like a rocket to a wide ratio tuned down race tractor. I had to sell my crf so i could ride woods with my kid where i could putt some also.............My fix was the WR. Dont get me wrong the wr has power, just nothing close hit wisee to any of the R model 450's

  • mcpga

Posted September 01, 2011 - 12:44 PM


That's all good to know! I just do a lot of trail riding these days, so I'm not so much concerned about added a ton of performance. I wanted to make sure there was nothing wrong with my bike. I think guys have answer my questions thank you!

  • Krannie McKranface

Posted September 01, 2011 - 01:00 PM


I've owned a CRF450R and a few WR450's.
CR powerband is quick, more violent, and more potent. But all that is useless on a single track trail.
The WR is no beast; it's a fantastically stable, smooth, reliable bike with a great powerband. Do the uncork, jetting, exhaust and it will be more of the same, and run cooler and smoother too.

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  • mcpga

Posted September 02, 2011 - 11:52 AM


Don't get me wrong, I love the bike! It's awesome on the stuff I ride! Any suggestions on an exhaust!

  • ww44wrf450f

Posted September 02, 2011 - 02:55 PM


I love my Dr.D slip on on my 06, 03 from what I have read here in the forums is the most powerfull wr to date. Mybe the rings / valves etc are tired? The bike starting easy is a good sign though? I would start with a good slip-on muffler.

  • Krannie McKranface

Posted September 02, 2011 - 05:03 PM


Just getting your leak jet and fuel screw adjusted makes a big difference in how the bike reponds to throttle. That and your sag. If it's soft in the back, it will squat upon throttle and feel powerless.

  • tribalbc

Posted September 02, 2011 - 07:55 PM


That and your sag. If it's soft in the back, it will squat upon throttle and feel powerless.

Rebound is going to effect this alot more than sag.

  • Just_a_trail_rider

Posted September 03, 2011 - 09:57 AM


Don't get me wrong, I love the bike! It's awesome on the stuff I ride! Any suggestions on an exhaust!

Just open up the stock exhaust and you will be fine. I run the stock 05 exhaust with the PMB insert. Cheap, quiet and it works great. I have an FMF factory 4 in my garage, but its louder and I am no faster or slower on the bike with it.


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