JD Jetting - other carb changes required on a '99 WR400


1 reply to this topic
  • Brian_in_Long_Beach

Posted May 26, 2004 - 01:55 PM

#1

I have a '99 WR400 that I've owned since new and I'm finally getting around to fine tuning the jetting on. The ACV/octopus was removed per Clark's instrucions when I got the bike and I've only fouled a plug one time - at Downieville in first gear at ~7000ft. That plug has been in the bike since Sept. '01 w/o any problems. I'm pretty happy with the bike as is - 48PJ, 172MJ - I think, and a DVP needle - don't remember the clip position, WR timing and a stock exhuast w/Thumper Racing Quiet Core (gotta pass 96dB). I've only felt the need for more power 1 time at Moonrocks while trying to keep up with a 520EXC and 501FE on a uphill two-track in perfect soil. The 400 was just out muscled. What it comes down to is I'm a lazy bastard and I have something that works pretty well and starts very easily.

What other carb mods besides the accel pump squirt duration are required with JDs jetting kit - PAS, MAJ, etc? For those running the R/C axle collar how are you keeping dirt out of the accel pump diaphragm?

Thanks,
Brian

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • The_Missile

Posted May 26, 2004 - 10:14 PM

#2

I used stock jetting and went from there. I put on CRD pipe which had me drop my main to 168.
I had a 43 pilot but cjanged to a 38 but its too lean, massive pops on decel. I'll be putting the 43 back in. All this with the red needle on clip position #3 (from top). I live at approx 2000 feet and its +-20C here now.

Keeping the diaphrgm clean....cant remember which one I am using but its one of the following: the rubber cover from a mountain bike shimano v-brake OR the rubber cover from the barrel adjuster of an XT/XTR shimano mountain bike rear derailleur. Not perfect, but best i've fouind so far.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.