Might be too rich or your idle a bit too low. My revo was doing it and I hat the bottom end a bit rich. It kept flooding. I leaned out the whole motor and left the low end. The idle was then fine. I ran a tad hot after that... but strong. Probably just needs the needles fiddled with.

Also, how much fuel is through it?? May be the beginning of a worn piston/sleeve.