I understand the whole jetting thing for the most part, but could something else be wrong? I have a K&N air filter, Greedy er... White Brothers exhaust, and 3 1" airbox holes, and my elevation is about 800 ft above sea level.
I have been trying to get the jetting right on my 400EX for about two months now, with little success. Today I got two new spark plugs, and decided to rip into it again. I rode for about an hour with the new plugs to get some color to them, and then started doing wide open plug runs. I first tried the 160 I have been running (the whole time thinking I am ruining my motor from running lean), and the plug was as white as Marilyn Manson's skin. I went right to a 170, and it was just white. I then tried a 175, and I got a gray color. Now I am at a 180, and it is a darker shade of gray. I know myself that anything over a 165 - 170 main jet on a stock 400EX is crazy, and I am at a 180, right where I was when I last asked about jetting. I have raised the needle one notch and it is the dynojet needle that comes with the jet kit (which I found worthless).
I have checked every intake point on the quad, and everything is looking good. I cleaned my filter yesterday, and the petcock flows just fine. The carb is all clean, and as far as I know, everything is tip top on the whole machine.
My question is, could something else be wrong to create this condition? I don't know of anything, but maybe I am missing something...
The quad ran fine with the 160, but the mid range feels choppy, so does anyone have any suggestions for a needle position (Dynojet needle and I don't have the stock needle) with my setup? The 3/4 to WOT is choppy now with the 180, and got worse as I went up from the 160 to the 180.
In a perfect world, someone with a WB exhaust, K&N filter, and airbox vents or no lid could tell me their setup, so I could give it a try and work from there. Thank you so much for any help you can give me.