Anyone have a Canadian WR450? Hows the Jetting?

I have one and it has a slight hesitation at 1/4 to 1/3 throttle. I moved the clip down one position to the 5th slot and didn't seem to make much difference. Any Ideas?

I notice it more on the street than I do off road and on a Track. Probably because off road I am over 1/3 throttle more often. This bike is Tall, but it is perfect for what I bought it for.

Street Plate, Baja Designs Kit, (not yet installed) Trail Tech w/Billet Mount, Pro Taper, E-Line Frame Guards, Fork Guards and Skid Plate, Cycra Hand Guards, YZ 450 Muffler W/Pro Moto Billet Spark Arrestor(not yet installed), Zip Ty Fuel Screw & Drain Plug.


RM250 96

XR70 01

PW50 92

Try raising the clip and see if lose the hesitation and if you find a lean condition (weak acceleration) a different needle with less taper should lean out the bottom of the needle. :)

I had noticed the hesitation when i received mine. i intalled i yoshimura rs-3, modified the air box lid, and switched from 160 to 165 main jet and have no hesitation at all.

Balcs, I too have a Canadian Wr450 that has the hesitation at 1/4 to 1/3 throttle. Did you find the cause? I have moved the needle, changed the main & pilot. The pipe doesn't seem to matter. Have used stock pipe, a 1998 Wr400 pipe, with and without a "Vortip". Have a "Q" pipe coming. So far nothing has taken away the hesitation. Great bike. Loved the rocks in Moab.

How did the FMF Q pipe work out for you? Did it help at all with the hesitation? Did you have a hesitation when you were riding at a constant speed and it would hunt up and down just a bit?

can i have all the jetting figures off of one of you please. ACCURATELY. not standard needle on standard clip blah blah blah!

it's either your needle taper start or the straight is too fat. the other thing is the APJ or a massive PJ.


IceBox, the "Q" is on. I have only run up and down the street-seems to be better, but not totally gone. Son Dan (WR450) & I are leaving tomorrow for Tonopah Nevada. We are doing a 4-day 1000 miler. I will let you know how it is working.

Taffy, as of this moment the jetting is back to "stock" Canadian factory spec. My dealer mechanic went up & down with jets and needle position. Went back to stock because we saw no improvement. He was thinking maybe electrical? The plan now is to run bike with new "Q" pipe and work some more on it if there is no improvement. I know this is a blah blah blah! but I really do not remember the exact sizes & position for you.

Sounds like fun, have a great time.

Do you have the old type end cap that is rounded or the new one that looks similar to the T-4 end cap? I emailed FMF for clarification but haven't heard back yet. There website still shows the rounded end cap but says the Q is "new". :)

I have the "old" type. The newer one sounds interesting. I will probably go to it after I hear what you guys have to say. Leaving in one hour for the ride. Will let you know how it turns out.

Just back from the Nevada ride. 16 riders did 850 miles. Tonopah, Ely, & Elko. Lots of dust. Only one flat tire for the group-great trip. The "Q" pipe did not take away the "Hesitation"! Bike still does not like to run on highway or dirt roads at 1/8 to 1/3 throttle. As the air filter got dirtier and problem was worse. After cleaning filter & changing plug (pretty black) the bike was back to previous hesitation. Get it up on the throttle and it runs better-justs doesn't like low throttle stuff. Ride was between 4000 ft & 9000ft. Funny part of all this is that son Dan & I have the same bike, except he has a Pro Circuit Pipe. Both Canadian, same dealer, and no jetting differences (we think). His bike has no hesitation. Using GPS, on the pavement, his goes 100 MPH, mine 92 MPH ( both using 15 tooth sprockets). Next step is to open both carbs and see what we have for Jetting. Hope the jetting experts can help me. Our previous four WRs never had anything like this.

Steve, if I remember correctly, my manual shows Canadian models come with a needle 3 steps richer than my U.S. model. Sounds like your needle might be a bit rich for your elevation. A dirty air filter making it worse would seem to support this. I am running my U.S. model at about the same elevations as you with a 48pj, 155mj, and the stock needle in the stock position. Bike ran great @ 5-6000'. Just installed a Power Now and it now runs rough @ 1/4 throttle. Pilot is now to fat(RPM's hardly change with fuel screw seated). If you needle is in fact 3 steps richer, with a 48pj(stock Canadian, if I remember right), your probably way rich at your elevation.

I'm no expert, just thinking out loud. :)

It's OK to think out loud. I am looking at my manual right now. I am confused! Does the jets & needles marked (STD) mean all WRs except USA? And the ones marked *(STD) mean USA WRs? If this is the case, my WR has a #DUT needle & yours a #DUQ. I believe by the chart that a #DUT is (3) leaner. Doesn't really matter, bike runs bad, and I need to get into it and see what I really have-and fix it. Another difference between son's bike & mine is I got 32 to 35 miles per gallon, he got as much as 52 miles per gal. Major problem when we needed to go 170 miles without a gas stop. Sure wish someone would make a 4 gallon tank.

Ok, lets see. I'm looking at page 2-8. It shows a DUT for U.S and a DUQ for Canadian as you said. Also #48pj for CDN. Arrows pointing left in the CND column I think means the same as U.S. column. Then on page 7-8(tuning) it shows DUQ at the rich end of the chart. An * means standard for Euro and Canadian. As I understand it, your bike should be considerably richer stock than U.S. This still wouldn't explain the difference in mileage between yours and you sons though. Riding style maybe? :) It does seem extreme. Also, on the right side of the carb, behind the rectifier, there is a plate that accesses the throttle linkage. If you remove the plate you will see a screw with a spring. This screw adjusts the accelerator pump. You might try experimenting with turning that screw in(clockwise) 1/2 turn. I have heard a lot of YZ owners do this to get rid of the low end bog. I tried it on my WR in its current rich condition and it seemed to help. I'll probably play with it again once I get a leaner pilot in. Turning it in leans the accelerator pump, but I don't know if changes volume or duration.

Again, just thinking out loud. I was thinkig of trying a richer needle at one point, because I figured the U.S. models were jetted lean to accomodate all the EPA garbage. But the bike seems to run pretty good. I haven't taken a plug reading lately, however, since it's such a pain to get out. I guess what I'm trying to say is, I'm just guessing. All I know for sure is, this thing ROCKS! Good luck. :D

My current jetting is:


DUT needle-4th (stock)


Installed Power Now and 48pj is definately rich now.

Zip-Ty fuel screw(I play with it constantly, so I don' know where it's set at)

Oh yeah, I got around 24 miles per gallon at a race last weekend, been getting as much as 26 or 27 on weekend rides. 170 miles is definately out of the question.

You are totally correct in reading the charts-I had it backwards. Tonight, if time permits I will be into the carb to find out what I actually have. I really need to find out want son Dan has too. Probably will not get into his carb until after he does the Vegas to Reno race on the 27th. Talking about riding style-Son Dan is a racer. Wheelies in 4th & 5th gear are his thing. My style is much more conserative-my milage should be the better of the two.


I have a 2003 Canadian WR450. I fixed the 1/3 throttle hesitation and backfiring on deacceleration by changing the needle to the stock USA YZ450 needle at the 4th clip position from the top.


Are you running the stock sealed Canandian pipe? What altitude are you at?


I have a modified stock pipe with the supertrapp system. 6 discs and below the 96db limit. It's also USFS approved. Altitude is 9,100 feet. 155 main, 40 pilot, 2 3/4 turns on the air screw, stock 2003 YZF needle at 4th position. Gray wire newly reattached (I've been doing tight hare scrambles and need the nuance of retarded timing at low RPM). Also accelerator pump screw removed (I need to start a new thread on this; it eliminates any hesitation). Also try octane booster if you can't get 96 octane gas.

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