yz jet needle?

9 replies to this topic
  • onyxxx

Posted September 15, 2002 - 09:53 PM


Does switching to a 02 yz jet needle make your wr 426 run more rich or lean? I have an opened exhaust, and lid off the air box with stock jetting. Plug looks like bike is running rich. I am inexperienced with carbs, and trying to understand the jetting process. This website has been a very useful tool. Thanks


Posted September 15, 2002 - 11:00 AM


The YZ needle Sucks when compared to the OBEKN needle. The Ekn is much more explosive and power is maintained all the way through the powerband.

Bonzai :)

  • onyxxx

Posted September 15, 2002 - 11:29 AM


From my understanding, the OBELN needle is from the wr 250,(not sure from what year). Should I try this needle, what clip position is recommended, and would this needle make my bike run richer or leaner. Would other adjustments be necessary with this needle? Thanks

  • RSA210

Posted September 15, 2002 - 02:38 PM


Onyxx,It's kind of hard to believe yor bike is rich,you don't mention any symptoms as to how the bike is running???I can tell you that the only difference between OBELN and OBEKN is a half clip,these needles are almost identical to each other according to what James Dean told me when I trialed these needles a couple of months ago.I personally could'nt make any progress with either one of these,due to the restriction of my Euro exhaust on my Canadian model.Others will have different results with more open Exhausts.I would encourage you to familiarize yourself with the carb and jump in!!!!!!You can always put it back.As for myself I will be doing a YZ exhaust and re-evaluating my jetting from there.Just do one thing at a time and write your results down,a small minority will get it right the first time.you will always wonder if you don't try.Roost on my friend :) :D :D

  • HaremScarem

Posted September 15, 2002 - 03:29 PM


I tried a few needles and finished up with OBELN.
Check my settings in the signature.The bike is a whole new beast. If you want a real fun time, go YZ timing.
To Quote a famous TT'r. " It will rip the hair of your *ss" :) :D :D

Good Luck

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  • onyxxx

Posted September 15, 2002 - 06:22 PM


Harem, I noticed that the only change you made with the eln needle was to your main jet which was increased from stock to a 168. Did you do your jetting before or after the yz timing. I plan on leaving mine wr timed at least for now. Also, how many turns out is your pilot screw. I ride in Michigan, is your climate comparable?

Also, I said my bike is running rich because when I pulled the plug, it was black and a bit wet. As far as how the bike is running, it starts one kick every time, and runs to my satisfaction, however I do feel sometimes a cutting out when on the throttle, say in fourth gear. Also it seems like I could get faster acceleration from bottom through mid range. If there is performance to be gained from jetting it, I am willing to give it a try. Any info would be greatly apprecaited. Thanks

  • HaremScarem

Posted September 15, 2002 - 11:15 PM


I tried the pilot circuit with 40/75 45/75 45/100 48/100 and 38/75. I thought the original (Stock)42/75 was the best. I also tried 160,165,168 and 170 mains, on all clips. Changing the timing does not effect the jetting, but I did re-jet prior to going YZ. My bike starts 1 or 2 kicks cold, and 1 kick hot "Every Time",with no hot start required. I ride in PA at about 200 to 1600'. I did the BK but left the squirt at 1 second at WOT.
The wet plug could be from the accelerator pump squirt duration and you wacking the throttle.
Do the BK and try some new combo's. There is a TON of jetting info on this site.
Good Luck.

  • onyxxx

Posted September 16, 2002 - 04:36 AM


Thanks for the info. I think I will try the eln needle and go from there.

  • onyxxx

Posted September 16, 2002 - 06:05 AM


Almost forgot, where does the OBELN needle come from. I have the part number from doing a search, however I'm courious what bike and year it is from.

  • HaremScarem

Posted September 16, 2002 - 07:19 AM


YZ250F option
Check your local Yamaha dealer


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