high altitude jetting

[USAF400EX]

Can anyone provide any high altitude jetting specs? (3000-6000ft) I have a k&n filter, no airbox lid, and a white brothers e-series pipe. Any info will be greatly appreciated.

[RideRed400EX]

If the bike is jetted properly now and you are going to high altitude I would drop down one on the main.

[JabberJaw]

(3000-6000ft)????

Those are some serious jumps!

[Dave310R]

I don't know about any specifics, usually that is hammered out by trial-&-error depending on riding conditions. As a general rule, as you increase in altitude, you need to run leaner. You already have a K&N filter with no lid which means you're getting plenty of air. You just have to try different jetting at whatever altitude you're running.

[USAF400EX]

well thanks for the replies. My quad was jetted for high altitude direclty from Honda. I just need to know if I need to go up or down with the main for the extra air flow(I just put the mods on and it hasnt been jetted yet) Also should I just have to change the main, or do you think I will have to screw with the needle and pilot also. Thanks guys

I also have a WB E-series with a FMF power bomb header, K&N, No air box lid, and a WB CDI. I'm at 5500ft and I run good with a 163 main with the needle clip dropped on position from stock. Anything less for me is too lean. Hope that helps.

[JB's 400ex]

I don't know if this will help but I run a E-series at about 2500 - 3000ft, everything else stock and I uped the main jet to 158 and the pilot to 40 and it seems to be running pretty good. That might give you some reference.

[tprender]

When I went to Colorado to ride last summer, we stop at the Honda shop in Colorado Springs to ask about what jetting and was told for every 1500ft up from your higth go down one size on the main and for every 3000 ft go down one size on the pilot. I ended up with a 152 main and a 42 pilot at about 9000 ft. and it ran very good and had a great time. We are going back again this July.