WR450 jetting Q's

Fantastic! The JD jetting kits will solve a lot of our issues with getting the jetting to work well on our bikes! I will be checking each day to order them from JD on the TT store. It would be so nice not to rejet every weekend. Making this bike work over a wider range of air conditions and we will all have more time for riding. :)

Just to let everyone know I am very impressed with the EMN needle in my bike. It is perfect. I put it in last week and it just feels great everywhere. If you have not tried it do so. JD, Taffy and others are right on about this needle. It rocks! :)

Indy! Does that needle have a Yamaha part#? Dealer has a hard enough time finding the stock stuff as it is. Thanks!

Smoke :)

Order from Sudco 1-800-998-3529 talk to Paul. I got the EMM & EMP needles for higher altitudes as well. It is the best set up by far and I reduced my pilot to a 45 PJ/ 70 PAJ with that combination EMN needle! I am pumped at the performance! :)

I have a technical question for taffy, jd, larryco, or whoever can answer. The needle straight never goes into the needle jet. It can't because the needle is way too long. This is with the dut and ncvq needles I have to play with. The straight is still about 1/4" from the jet when the needle is bottomed out on the main jet. When I took the main jet out of the needle jet, the straight would get to the jet. However, the straights on both needles were too big to actually go into it. How does this affect jetting if the first two letters are the same (ie ekp and ekr)?

WTH... An eka should act exactly the same as an ekz. It is the same distance from the top clip to the point at which the diameter is 2.515. Having the same taper angle, they should act EXACTLY THE SAME in the bike. The only difference in these needles is in the part which never goes into the needle jet. :)

If anyone doesn't believe me, I've got a picture of the needle sitting in the needle jet while it's bottomed out on the main jet. I just need to know how to post it.

Another question. Has anyone ever tried an F series needle? Like fkp.

I think most people are staying with the D and E tapers for the WR bikes. I have not heard of anyone using an F taper.

I see the JD jetting kits are in the TT store but I only see 2 needles and 4MJ and an extra needle clip. What about the PJ and the PAJ? I was under the impression that it would have everything I need to rejet with perfect or very near perfect results. Will I need to buy some extra jets for PJ & PAJ to make this kit work for me?

Smoke :)

well here are my specs I think i got one of the first JD Kits :D


james dean red needle 4th clip position

170 main

1.5 turns out

Baja baffle in

air box opened

I put the JD kit in and gain a big inprovement down low of stock.The thing screams from cruising to the rev limiter real quick.I'm real happy with the jd kit and hope to get some more power once i get a decent pipe on the bike. :)

How's the off idle response? If you open the throttle wide open from idle is the bog reduced or eliminated? :D

I have no bog off idle. I have never had it. I think the fuel air screw has enough adjustment to leave the pilot circuit stock. I had mine at 48PJ/100PAJ with 1.0 turns out and it ran fine. I just changed it to bring it back to the center of adjustment but it was not really necessary. I just rejet a lot. :)

I gained alot down low.It had quite a bit more power and popped up the front wheel easier.I have been playing around with it and think it is more responsive all through the power range.

I never did have a off idle bog though.

Thanks Steve, I just placed my order today! Are we going to add TY Davis products to our TT store? I would like to buy more stuff from our store to support this forum. Thanks again. :)

Are we going to add TY Davis products to our TT store? I would like to buy more stuff from our store to support this forum.

We will be adding Ty Davis products along with hundreds of other products in the next couple of weeks. Keep checking the TT Store.

Thanks for your support!


Current jetting so far..no bog or hesitation, e-start first time almost every time.bike idles well and doesnt overheat at idle or on the long slow hills we have around here.

160 main

48 pilot

stock needle

4-clip position

1-1/4 to 1-1/2 on fuel screw

70 PAJ

PMB insert


RDR you have got to try a different needle. If you modify your exhaust and intake you will find that the stock needle is unworthy of the bikes performance capability. I was stuck with the stock needle because the stock muffler with an insert still did not flow as good as my new pipe. I am amazed at the Thunder Alley ceramic coated 96db Sparky pipe. I could not use the stock needle in any postion without constant popping. I finally got the EMN needle and this combination works great. I went through NCYQ, NDJN, OBEKQ, OBEKP, OBEKN, OCEMP, OCEMM, needles to get to the OCEMN needle. I have tried all the needles recommended on this forum. I just ordered the JD kit and I think it will be even better. The stock needle seems to only work well with the bike corked up. I will give everyone an updated on the JD needles as soon as I test them. I am going to Colorado in a couple of weeks and I will get to test the high altitude needles as well. Stay tuned. :)

Placed my order for the JD kit. Hopefully these kits will help these WR's reach full potential. I am somewhat amazed how different the carb jetting specs range from member to member with very similar modifications and elevations.


Thanks for all the great info. I am interested in your comment on the stock needle. I have baffle out of airbox and cut out the left number plate. Stock pipe/no insert. No bog or pop. Is there more to be gained by going to the JD kit or different needle? Are you using the complete Thunder Alley pipe or just the cannister? I am currently running the stock pipe open but want to quiet it down. In reading all the posts, I'm not convinced that putting an insert in the stock pipe is what I want to do.


Indy... would love to find a needle that works better, but it seems that a lot of TT riders are using different needles with different results. such as my situation, I am using the stock needle with NO bog or hesitation and power delivery couldnt be smoother but I would love to get a snappier response out it. I have leaned my setting as a test in the past which only created a hesitation and bog on the lower end, also making the bike start harder and overheat at idle. I plan to keep listening for that golden setup out there.

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