New guy: 97 KDX 200 running rich

[thefriends03]

I have a 1997 KDX 200 with a Kustom Kraft 240cc big bore kit on it. It has an FMF Gnarley pipe and and FMF Turbine 2 spark arrestor/silencer on it. I am pretty sure the carb is stock - Keihin PWK35 is stock, but I could only find PWK on the carb. The main jet is 145, and I am not sure about the pilot jet right now. It has the stock needle and the clip is on the highest setting, making the needle the lowest it can be. It idles fine, runs great, but the plug is black. I haven't fouled a plug, but yeah, it's black. Also, I am going through gas like it is going out of style. I am sitting at about 4750 elevation and ride every now and then with changes of about 1500-2000 feet during the ride. But for the most of my riding, we are only talking about 500 or so feet in change of elevation. Any ideas/suggestions about jetting or needles to help it run more lean? Should I change the main jet to a smaller one and go from there? Should I change to the next leaner needle and go from there?

The tech tips on the justkdx page say that if the needle clip is in the highest position to go to the next leaner needle. I just would like some suggestions on where to start.

Thanks for any help.

 

[eagles22793]

I would put leaner jets in the carb and then look at the plug to see what it looks like

 

[thefriends03]

thanks. that's what i figured, but i wanted to bounce it off others. my only concern is that it is lean already compared to stock, and with the big bore kit in it, you usually would go richer.