WR450 - YZ needle?

I have done all the free mods. Riding elevation is 1000-3000 feet. 160mj, 50pj, pilot screw 2 turns out stock needle position. I turned acc pump adj 1\2 turn clockwise per TTer's advice to cure off idle richness. Bike runs real strong with no hesitation. Will I gain any noticable increase in performance by going with the YZ needle?

Thanks in advance,


I had luck with the YZ needle with an open pipe only or with a YZ cam. It was too rich for a exhaust insert and WR cam. I prefered the WR needle with that set up. I have since sold my YZ cam (too fast mid&up-lost bottom end) and am playing around with q,p,n type needles but I still prefer the stock WR needle at this time. The biggest problem I see is which YZ needle to get. I have five of them and still trying to see which taper works best for my Thunder Alley Pipe, Twin Air filter, Air box with large cut out. If you are happy with the stock needle leave it alone or be prepared for hours of tinkering and rejetting to find what works better for you. I will be the first guy to sign up for A WR500 fuel injected model so I can tune my bike with a lap top and a power commander like I have on my R1 :)

I saw a little saying on jetting a while back. Went something like this.

The first 90% of your jetting work will take 10% of your time, the last 10% of the work will take 90% of your time.

Getting it dialed perfect is a job for sure.

I use the YZ needle in my WR and like it but when it gets hot out I may switch back to the WR needle. My bike has the free mods and the Pro Moto pickle, runs good and is quiet.


I just put the stock YZ needle (4th position)in my 2003 WR and the performance increase was about 20% (a lot)I'm at 9,100 feet, 155 main, 42 pilot, 1 3/4 turns on air screw. Supertrapp exhaust with 6 discs (unplugged without scaring large animals)

Tim :)

Anyone know where to get needles and jets online?


Tim, Indy450 said there are a few different YZ needles. What one are you using? Do you have the part number?



The YZ needle that I'm using is the stock YZ one on your dealers microfiche "NCVQ", 4th position from the top.

If you're pipe is closed course (loud), get the one richer needle. Try 5th position from the top. Side by side comparison of the stock yz to wr needle; the YZ is thinner = more fuel.


I'm also at 9,100 feet, so your mileage will vary.

Thanks Tim, I'm in Colorado also and ride a lot at your altitude and above. I'm using the stock pipe now so I'm not able to open it all the way (well all the time anyway).

I'm riding around 3k feet. Currently using the NCVQ neeedle clip position 4. I tried position 5 but it's too rich. I may go back to the stock needle clip position 5 since I still seem to be a bit on the rich side. :)

I have been looking around online for a source for a yz needle. (I am not too happy with the local dealer's parts and service dept.) Yamaha of Troy.com has an online micro-fiche that shows the standard needle as NCVQ but will not let you select the standard needle to purchace. I called another dealer and the parts guy told me that it is not avalable yet.

Anyone have a suggestion where I can find one?


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