I think, not 100% sure, that when your bike revves real high when you start it with the choke on, then that means the pilot is too lean. I would mess around with the airscrew to richen it out alittle, if that doesnt help then you'll have to go up in the pilot jet until it stops doing that. Because if it revs really high when you start it, it has the chance of cold seizing. My bike used to smoke alot and spooge alot, so I went down on the main jet size and up in the needle size(bigger number on needle means wider the needle, which means less fuel gets by it, so leaner). I have an '87 cr125 and went down from a 162 main jet to a 145, and up one size on the needle and clip in highest position. I also run a BR8ES plug, the 9 will foul when I start the bike up the next day, even if I road hard the day before. The step down may seem extreme, but it works, and theres no lean bog and theres no extra wear.