Sorry..but jetting help needed!

3 replies to this topic
  • OzAqua426

Posted September 19, 2002 - 12:54 PM


HI guys,

Need some direction with my jetting!
Firstly I ride a '02WR426 at sea level with standard euro exhaust. Have done bk mod and removed airbox lid.
OK now I put the OBELN #3 the rest is stock. With this setting the top end was very boggy from about 60kph, so I moved clip to #2 and was much better a bit higher up(nice snap in 1st 2nd and 3rd). But still has a bog up high (about 70kph, 4th and 5th). There is no poping or backfiring to speak of.
I want to stick with the eln needle but need help getting the mid to top end dialed in. What should I be looking at for more 'snap' here?


  • ratbiker

Posted September 19, 2002 - 01:39 PM


I have an 02 my needle position is 3 and a 155 main my kouba t is 1.0 and i have bk mod i adjust per altitude i live at sea level and have been riding (summer) at runs great at home i adjust when we ride(b-k mod and kouba seems to help alot).waiting for snow so i will have to ride at sea level again but for now these specs rock! :)

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  • Snapper

Posted September 19, 2002 - 06:52 PM


Aqua - interesting to hear from you on this forum.

When I put in the OBELN with the stock jetting my bike jsut fouled plugs at low speed and coughed at high speed.

Check the spec's in my profile - though I have now gone to 38 pilot.

when the bike is running it rocks but I am still getting some bog and gooey plug after idleing (eg at a start line or waiting while someone opens a gate. when I take off it is as if the plug is fouled and it takes a bit if WOT to get it cleared and then it rocks again.

I haven't done the BK mod yet and some of my problem may be the occasional twist of the throttle whilst waiting (old 2 stroke habits are hard to break) causing APJ squirts and fouling.

Stock is a 165 main and after consulting some experts I have ordered a 160 and a 155 cos I reckon that it is pumping too much at the bottom of the needle.

When I had the stock 42 pilot it was fouling plugs which you only really noticed when you moved past 1/4 throttle and the plug wasn't buring clean. Evetually it would foul and stop.

It got better with the smaller pilots but it is still not quite right.

I have also done a heap of charts on the JD jetting guide in respect of the changes I have made and potential changes to fix my problem and reckon that

MJ 160-155
PJ 40-38
clip 3-2 is the way to go.

Interesting that you are still coughing on clip 2, suggesting that the smaller main is the go.

I would be interested in some expert opinions as myn still not quite right.


[ September 19, 2002, 09:56 PM: Message edited by: Snapper ]

  • OzAqua426

Posted September 19, 2002 - 07:12 PM


Hi snapper,
Well I've been reading jetting info here for weeks but have only just tried to put it to use!
Thanks for the info that at least gives me an idea.
I have a 160 MJ at home which I think I'll try first, then if need be mess with the needle.
I was surprised how well it ran with just the needle change and the rest stock, was heaps better down low(1,2 and 3rd gears) but the mid to top is still a bit boggy (hesitates then takes off). Which I'm hoping the main jet will help.

So do you think I should lower the MJ first, or should I be looking at the PJ and PAJ?
Want to make sure I'm heading in the right direction!

Aqua :)


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