Needle question

6 replies to this topic
  • crs

Posted September 06, 2001 - 08:30 AM


A request to the jetting gurus,
I need a little jetting advice. I have sorted through the archives and am having a tough time determining a good all around jetting. 00'WR UNI filter, airbox lid off, grey wire, BK mod, Big Gun exh. Mostly aggresive woods riding, 3000-6000 ft. More interested in bottom and mid-range. Looking for a good all around needle/jetting set-up to use as a base line.

  • John_in_Long_Beach

Posted September 06, 2001 - 09:37 PM


YZ timing or WR timing?

  • crs

Posted September 06, 2001 - 12:00 PM


I knew I forgot something. WR timing (for now). O do you suggest changing it right now while I have most the bike apart?

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  • John_in_Long_Beach

Posted September 06, 2001 - 01:17 PM



Since most of the jetting specs come from many R&D hours from other members on the site, I can tell you some general guidelines and the jetting specs I use.

Regarding YZ timing, the general consensus is that most people like it better. How could you not like a more immediate throttle response. Even if you are a trail rider (and I am sure some will disagree) you need to be able to lift the front wheel quickly sometimes.

2nd reason for going to YZ timing is that most of the jetting experience is applicable to YZ timing. I never tried to get the "right" jetting setup with WR timing, just went straight to YZ timing. I figured all of the experience of different people on the forum was good enough for me.

As for my settings they are as follows.

YZ timing, air cover removed, DSP tapered header and exhaust (very free flowing), EKN #4 needle, 172 main, 48 pilot, 100PAJ, 200 MAJ drilled to 2.26mm (226 - #43 drill), and MAJ passage drilled out to 2.78mm (7/64), and about 3/4 - 1 turn out on fuel screw.

If you have a more restrictive exhaust or a higher altitude you might go with leaner settings.

Fortunately, I did not have the pleasure/frustration of fiddling with the 1000's of combinations to get the above settings just right. They come as courtesy of many other forum members research. But the beauty is everytime I have tried some settings they have worked perfect right from the start. No aftermarket jetting kit I ever bought for my street bikes worked that well first time out.

Hope that helps.

  • TeamScream

Posted September 06, 2001 - 03:57 PM


I love this place...I really do
Guys like you John and James (and many many others) make it such a wonderful resource. Sorry for stepping on this thread but its just amazing to me (John did I get an Email from you?)

01' WR426,YZ timing,EMP #5,#48Pilot,#100PAJ,#172 Main,BK mod,stock pipe-no baffle, open airbox,Gray-Wire Pulled,K&N Filter, throttle stop mod,CA Street Legal (sort of) Pure Super Motard w/17 in. wheels, 15/46 gears,ProTaper bars,

  • crs

Posted September 07, 2001 - 06:13 AM


Thanks for the info. I guess I'll add YZ timing to the list of things to do while the bike is apart. It is hard to turn down free throttle response.

I know what you mean, I now know more about my new WR than all my other motorcycles combined. Hey, we are in the same area, I think a buddy of mine talked to you the other day by the RB pier. I'll keep an eye out for you, I'll be on the other street legal WR in town.

  • John_in_Long_Beach

Posted September 07, 2001 - 07:50 AM



I didn't e-mail you in the last couple of days?
What difference did the BK mod make to your bike, I notice you have about the same jetting. And what does BK stand for. From what I have read, it is just a way to shorten the duration of the accelerator pump and to properly time it with the opening of the slide. Right?

[This message has been edited by John in Long Beach (edited September 07, 2001).]


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