So for a week or so i have been tooling around with my 06 250f and cant seem for the life of me to get it running right. To make the first part of the story short, I rode at a indoor track this winter and made it 1 lap around and the bike quit on me like it ran out of gas and couldn't get it to start after that. Well it took some time after that to get to looking at it, and couldn't figure it out, different cdi, checked and shimmed valves and what not, ripped it down to the piston nothing there and put new rings in it and what not. Turns out it was the kill switch all along and we kinda overlooked that, since the plug was getting spark. Anyways now its running but for some reason can't get it to run good. I did what most people say and changed up to a 42 pilot 180 main and the rest is stock, believe the clip is 4th notch down from the top. I added a white bros carbon pro exhaust, then went back to stock and it still doesnt seem to want to cooperate. I start it, choke out and it starts fine, go to push the choke in and about 50% of the time it idles down and then idles too low and dies. Other 50% it goes alright and you might have to keep your hand on the throttle but it comes around and seems to backfire a bit, nothing too bad but its there. I know, I have had it idled up and this helps a bit, but this isnt the main problem. When i went yesterday to get on the track, it goes alright for about 5 mins, and then it starts get a bog on acceleration or a load. Bogs when you goto twist the throttle and this is a bog that at times seems like it will throw you off the bars, it takes away that much momentum. It also backfires sometimes while decelerating. I know this leads to most of the time the pilot circuit but from my countless hours of searching anything bigger than a 42 pilot, theres another problem from what I have read. So I am kinda stumped, i don't have an aftermarket fuel screw so i just have to turn the carb and change it that way which gets to be a pain but was wondering what most peoples screws are at? I had the screw out 3 turns with the carbon pro on at this particular time. I checked the plug with the white bros on it right after running it with the new rings and it was a greyish white on the electrode and black (oily) around the threads of the plug which i think is normal for the threads. This was at around 2 ¼ - 2 ½ turns out on the fuel screw. Thought it was running a little lean. When I rode yesterday for the 5 mins described above I had the screw out at 3 turns which is what i thought was the max to have the screw out at, and took the plug out today and it was darker around the electrode. This with the bog. Went through and cleaned the carb today, put the stock exhaust back on, turned the fuel screw to 2 ¼ turns out, and started it back up and it does the same idling as described above, and backfires a bogs slightly on the stand. I have checked the airboot and rubber fittings around the carb for leaks, my hot start I don't think is stuck since the lever moves fine and I can take out the new aluminum fitting, which is a must have piece i think. I also have checked the carb slide plate to make sure the hole was down and not up. Unless I am misinformed, I thought going up on the pilot from a 40 to a 42 would be going richer, so I don’t understand why the spark plug was showing signs of being lean. Does a freshly ringed bike run leaner for a bit while the rings seat and would show on the plug? I might just being overly cautious as I dont want the thing to hatch on me, cause then it would be quite a bit of $$, but from what I have learned a greyish white plug isnt good most of the times. Any ideas would be appreciated since this is getting kind of old. Thanks!