I'm certainly no expert, concidering my last post, but might try leaning it out. I just had a similar prob., too rich. Don't listen to anyone who tells you this engine or that engine runs best at precisly X amount of turns. Impossible, they're all a little bit different. This can be a good starting point, but you must go through the procedure, to properly adjust the needles. Do you have the manual?
Do a search on needle valve adjustment.
--Rick

Tower hobbies says 2.5 turns out: http://www2.towerhobbies.com/cgi-bin...1&I=LXAVV3&P=7

OS says, for their engines, start at 2.5 and lean out for max performance, then adjust the idle mixture: http://www.osengines.com/manuals/21vz-r-manual.pdf