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I just picked up a KDX down in Utah and am in the process of doing the top end and getting it fixed up. I read the carb tuning info I could find and am looking for a little help setting it up for my altitude here in Montana, 4800ft and up.

The carb now has a 158 main jet, 48 pilot jet, stock needle. It was set up very rich when I test rode it in utah. But it did run ok.

mods on the bike are, FMF pipe (not sure which, fmf spark arrestor, boysen reeds.

Any recomendations on what main and pilot to try starting out when I put it back together? I plan to pick up a few, what is a good range of jet numbers to get?

Thanks for the help

The 'Desert' pipe will measure about 11 inches around at the fattest point---the "Woods' pipe will be smaller. Try a 42 or 45 pilot with a 140 main and clip the 1173L needle third clip from top---move that up or down a notch where it runs best. Those numbers work well for me at my altitude of 5800 feet- and should be close for the altitude you ride. You might stock a size up on each jet at your altitude.
Where in Utah did you get your bike? a 200 or a 220? ---Curious because I've seen a few of the Utah bikes.

I picked it up in Provo about two months ago. It was worth a trip down there to get it, considering motorcycles here in sowthwest mt are very overpriced. Lots of good deals to be had in Utah. It's a 95 and a 200. It ran fine but is otherwise a little rough, banged up pipe, purple handlebars, wierd atv clutch lever, lights not working. nothing major but I have taken it down to the frame and am going through everything to freshen it up.

Deseret Rider

thanks for the suggestions. I went with what you said, 42 pilot, 140 main, exception being a have the 1174 needle. It is a good starting point but i think i need to go richer. I am hoping you can give me a few more details on what type of terrain you ride, you mix raito, how lean/rich you are at low vs high altitude, anyting else you can think of. Thanks in advance

That 140 main might work ok for a 220, but it is WAY too lean for a 200. Be very careful with that! Too lean of a main jet can easily hose your cylinder and main bearings. That's the main reason I don't like to suggest specific jets for someones bike, but rather direct them toward the jetting sticky here: http://kdxrider.net/forums/viewtopic.php?f=105&t=1156 . I'd start with a 155 main and 45 pilot and go from there. That combination is general a safe starting point for most 200's. You may end up as small as a 150 on the main, but it's very unlikely that you would need to go smaller than that on a 200 at any altitude.

I was starting to think I am too lean and was gonna try and get some more jets today. It seems to run good, but not great. I set my needle in the richest spot yesterday on a huntch and it made a big improvement on how it rode. My plug looked ok when I pulled it out, but it was an old one that was really black. I was getting some white smoke though, but no sponge, so I was wondering if that was being caused by a lean condition, saw that somewhere on here that white smoke may mean lean and going to blow up soon, along with coolant and crank seals. But the very lean condition is what concerns me most. If it is dangerously lean I guess I am lucky I have just been riding on pavement a few miles at a time with light load and not much wide open throttle.

Opps I lied, I just checked my my jets, I actually have a 145 main in there, not the 140. I bought a 140,142,145. But from the sound of things I still need to go richer. I guess I am really glad I didn't start off with the 140, or else I could be hosed big time.

Julien D,

By the way, you are on the ball, you always seem to be the guy setting me straight. This is my first dirt bike, besides a trail 70 and I knew very little about two stroke motorcycles before I found this forum, so thanks for all your advice

Happy to help! I'm still learning of course, just like everyone else, but I do like to help if I can.

running a 155 main at 3500-4000ft.

I'm at about 3000 - 3500. Been running a DGK needle with a 150 main. The DGK is quite a bit richer than the 1173n though....

What kind of performance do you get for the DGK?

I am in 4800 ft, and will be riding up to about 8000 ft. I picked up a 152 and a 150 yesterday and installed the 152. Much improved from the145 that was in there. I have the 1774 needle in the middle position. I need to do a plug chop prob, but I Need to pick up a crescent wrench that I get at the spark plug with. My goal is to get the bike jetted on the lean side of perfect for a cool morning at 4800 ft hoping that it will still run well higher up in the mountains without getting to fat and fouling a bunch of plugs etc.

The CGK / DGK are kinda specific to the E bike. The DGK is very smooth, almost no hit, but good strong pull all the way through. Pretty much like the DEL for an H bike.

I'm at 1,000' -3,500 running 142, 38 DEK, RB carb

Mr. Wibbens wrote:I'm at 1,000' -3,500 running 142, 38 DEK, RB carb

That lean, huh? Got this RB carb sitting here, I think its got a 152/40 DEK. Guess I should order some jets! Haven't had a chance to test it, still need a few bits and pieces to put the bike back together.

Julien D wrote:

Mr. Wibbens wrote:I'm at 1,000' -3,500 running 142, 38 DEK, RB carb

That lean, huh? Got this RB carb sitting here, I think its got a 152/40 DEK. Guess I should order some jets! Haven't had a chance to test it, still need a few bits and pieces to put the bike back together.

and still starts easily when cold

I have not done a plug chop on it in awhile, but I'm not pingin or boiling over

been running the same jetting over a year now at least

I ran the 150/42 and DGK for a couple years I guess. Worked very very well. Should I assume the RB carb will want smaller jets?

Carvr runs his pretty much the same as I do

I pretty much set it and forget it anymore

If I go to the dunes at sea level I'd for sure fatten my main up, to about a 155