tune the engine?
For the idle mixture, I personally like it a little leaner, to make for easier starts. Try to keep it just slightly rich on both needles - if you can't get it rich on the idle and start it on the first 3 tries, turn it clockwise to make it a bit leaner. For the main rotor, keep it slightly rich (enough smoke, but not too much fuel coming out of the exhaust) so that it doesn't overheat. Later, when you get into more advanced stuff, you may want to lean out the main needle to get a little more power and RPMs for aerobatics.
Remember that your engine will last longer when on the rich side - more lubrication. Lean means that there is less fuel entering the carb, which makes it act up and go to higher rpms, but with less lube so it may overheat. This is an issue in helis, because there is no real direct flow of air over the engine other than from the engine fan itself.
Maybe call the guys in the hobby shop?
Ever stop to think, and forget to start again?