Translations:KAVAN AP09A - Instruction Manual/62/en

6. Once the engine starts, open the throttle to full, and immediately start closing the valve needle (leaning the mixture) by small steps (max. ¼ of a turn), until the engine runs smoothly without stalling. At this stage, thick white smoke will come out of the exhaust and the engine will sound as if it is running heavily (four-stroke sound). This is a good setting for a rich mixture.