WR400 carb jetting

2 replies to this topic
  • ash105

Posted December 01, 2006 - 08:00 PM


I've brought a "99 WR400 a couple of weeks ago and notice it bogs when accelerating from idle, sometimes stalling, also at full revs it starts missing. It also seems to use excessive amounts of fuel (80km per tank full). Apart from a procircuit pipe the bike is pretty much standard, could it be a problem with the accelerator pump? Also what size jetting should it have and setting on the primery jet. The person I got it off was pretty rough - missing spokes, 1 fork on 20 clicks rebound other on 10, comp not much better- so slowly working through the whole bike.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 5valve

Posted December 03, 2006 - 08:48 AM


Describing previous owner, I doubt carb was not "dialed in".
I recommend starting point with original settings, no matter the exhaust.
If you dont have the manual, download it and check settings.
98 and 00 have the same or very similar settings.

bogging, they say, is from acc pump, but it can not be adjusted, it can be modded though. (search - taffy mod)

too big main jet, raised needle..do affect consumption if mixture isnt done correctly.

  • ash105

Posted December 03, 2006 - 10:09 PM


I pulled the carb apart yesterday and found a hole in the acc pump diaphram so I'll replace that, set everything to standard and see what happens. Also a rip in the fuel tap seal so even with the tap off fuel could get through to the carb and leak while transporting.


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.