wondering how others with the stage 4 (440) kit and 42mm tmx have jetting set up?
just had a melt down and wanted to set it up right next time. Aaen origonaly gave me main jets 310,320,330 called them and they sent 360,370. It was still too lean, so I ended up going to local guy and buying 390,400,410,420,430. 420 wont allow it to open up all the way and 400 was way too lean so ive been runing with the 410 for about 6 rides in the mountains, seemed to run a little lean but just a little and plug was still dark coffee brown. so i thought it would be fine untill i ran it on the sand for about five minutes and scored and melted the piston.

 

I can't help with your jetting,i'm running a different setup.You may want to look for an air leak.Check your intake boot,check and make sure your drain plug didn't come loose on the bottom of the crankcase.Also you may want to look at the crankcase next to the clutch side.These motors have been known to crack in this area.Hope this helps.