02's with Taffy jetting

Sound off on your settings.

I'm taking the Plunge.

Thanks guys

specs below but still tweaking,Moving from warm 1500-3500 ft to cold sea level for winter,the way the bike has been acting i will probably still need to adjust some!But getting close :crazy:I THINK

I have been struggling with the jetting for a couple months now.

Currently running: 35pj, 50 pas, emm-3, 155mj, 160 maj

Also with yz timing, bk mod, grey wire, and WB E series with 5 disk (to keep it quiet), less than 1000'.

Ran a 38 pj & 60 paj for a long time but could never get it right until I went the 35/50. I tried the ELN but like the EMM because of the harder midrange hit.

I am pretty happy with the current setup but as soon as the weather changes I am sure to be tweaking again.

Hope this helps.


Here goes. My ’02 WR426 Jetting to Taffy’s specifications are: EMM #3, 158 MJ, 160 MAJ, 35PJ, 45 Pilot Air Screw. I’m still tweaking it, but this is my base setting.

I have the carbon fiber air box, which supposedly makes the pilot circuit richer. I was running a 40/60 pilot circuit and fouling plugs. Taffy recommended a 35/45 pilot circuit, which I am now running (and need to test more).

Twin air filter.

For exhaust, I’m running a YZ muffler, and a stainless YZ header P/N-YZR5GR93-10-SS.

Elevation is 800', and temps are in the'70's.

Good luck. :)

Look at my signature Brian.



What kind of climate and altitude do you ride in? I have been thinking about trying the OBELN needle, and I see the only other change you made with it was a bigger main jet. How does the bike run with it. I ride in Michigan at around 1300 feet.

Harem,Tell us what you don't like about your current settings? I tried OBELN w/stock Euro silencer,it ripped down low but no top end.How's your bike run NOW????

What did Taffy say? "You never know how happy you are until you are miserable" :):D :D

The bike runs real good with the OBELN. I ride at altitudes ranging from 200 - 1600'. I have no problems with my current settings and the bike runs very well at all levels, but I have this dam DISEASE that makes me always want to work on the bike. You know the disease I'm talking about. The one were you little kid approaches you for a pair of new sneakers and you tell him " Sorry Son, but the Yamaha needs new slippers also and if I don't do that first, I could slip and fall down and hurt myself and then I wont be able to work tomorrow and make more money so I can by your shoes next week" Disease. ( Just kidding )I have all the jetting listed in moderator Bill's signature in my mail box. I hear a lot of good things about Taffy's method of leaning out the carb, so the disease tell's me do it!

Thanks to all who posted and keep them coming...

Yeah Harem I have that disease too :D

Sooooooo......Enlighten me on your current settings.

BK Mod-Whats the squirt duration?

Did you do the ACV Disable?

Does the bike still have that OBELN "Tractor Pull"

down low? AND REV to the TOP???

You see I'm SICK too,I think will call IT the "I Gots Ta Know" Disease.GET WELL SOON :D:):D

Bk mod is at .5 seconds. I did not touch the ACV. the OBELN has great pull all over the power range. I tried the pilot at 38/75 - 40/75 - stock 42/75 - 45/75 - 45/100 -& 48/100.. the 42/75 was clearly the best. I also tried the main at 158/200 - 160/200 - stock 165/200 and 168/200.

the settings in my sig are the best of the bunch. It revs like a two smoke. I ride with a few guys almost every Sunday and they stay way back, because the 426 throws boulders. I just need to feed the Dam Monkey on my back and try taffys' jetting.

By the way, what did you guys pay for the pilot air screws from Sudco. I just received my new jetting and it was $3.50.

Harem,Thanks for sharing :)

I don't have the adjustable PAS just a 75 & 100 for now

Good luck w/Taffy settings :D

i did what taffy said, runs great. that air deal on the wr only, seems to make the motor run odd when comming back to idle. i have read about how to fix that but i am too lazy to do it. plus it runns so much better with taffys ideas on jetting that i'm like" well its soo much better than before i'll live with it"



I bought the adjustable screw and haven't used nor do I intend to. When you pick up the pipe or we go riding, I'll hook you up.



there shouldn't be any difference between the ELN and the EMM in the midrange. just in first gear/low revs really.

one thing everyone gets hooked on is the pilot circuit and needle diameter. so if someone has a * * Q needle and a 42PJ i'm sure it probably does work quite well.

to improve on it though you have to take a bit of a run and jump. the ELN or EMM needles along with a lower PJ will do the job.


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