RE: Engine tuning question
Idle too rich and the main needle too lean. Open the main needle a turn or so more and back the idle off a bit. Don't start a new engine at idle, start at about 1/4 throttle. But be careful as it will be running much faster right away. Open very very slowly to full throttle. You should be able to tell if it is starting to run lean or rich if you open the throttle slow enough.