I need opinions on my tuning: I've got a 2000 400ex, original motor, wrapped header, oil change. Rebuilt the carb and adjusted valves. After a lot of trouble with backfiring through the carb (signifying really lean) I'm running a 42 pilot jet and a 150 main jet. This helped a lot, but I'm still about 3 turns out on the fuel/air screw and a hair on the idle adjustment. It still coughs tons through the carb when cold, and nearly runs right with choke on during a cold startup. But once significantly warmed up (like I need to throttle it for quite some time to get it hot enough) runs great, idles great, and the plug looks good. Lots of power, feels great. I haven't messed with adjusting the needle, but it is in the stock position. I have no leaks around the carb on either union. I'm kind of at a loss here, and tentative to up pilot jet anymore sizes since it is already pretty big. Opinions?