Jetting for '00 WR400F

Need some quick help 2000 WR400F w/air cover off. Currently live in denver, app 5-6k feet in elevation and I'm heading to Utah in two weeks for a weekend ride. The elevation is about 4k. Any help??


I also have a 2000 WR400 also and recently did some jetting work that I really like. See my signature for changes from stock. It may stand some fine tuning but it feels really crisp and clean with no ill-tendencies. No decel pop, crisp on snap-open, great roll-on, etc.

Good luck,


I have question, I have a 2001 wr 426 and my specs that came from Baja Designs calls for my stock MJ 165 to a MJ 175 for 0-4k moab range, why does your spec. for the wr400 drop the MJ for a lower elevation? Should it not go up? Any help would be great. I will be riding with mski and don't want to be dragging him around the desert with a brunt ring. J/K :)

These things come from the factory jetted rich for the elevations I ride. Have you looked at your plug? I don't know anybody who is running a MJ that big on these at my altitude. Like I said it runs great, plug looks great, no bad tendencies, etc. Jet anyway you wish but IMO the 175 is the wrong way. In the absence of the time to do your own testing I would say run my jetting as a starting point and you'll be happy (assuming otherwise similar setup). You can always make adjustments at the motel. BTW, you won't find anything in Moab at 0' elev. You're looking at about 4,000+ feet.


the jetting in my signature is what you want with the euro/aussie canuck pipe at sea level.

if you're at altitude you need to go to an EKP needle (so they tell me!) and the MJ can come down by 5.

if you have an open pipe you should add 10 to my MJ and try the needle on the same clip or drop it down one.


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