Start out with the high-speed needle about 2 turns open from the closed position. Start the engine at about 1/4 throttle. Leave battery connected to the glow plug after engine starts and advance the throttle to full. As the engine runs at full throttle, gradually work the high-speed needle towards peak RPM. When the engine can hold a needle setting through an entire tank of fuel and be leaned to peak RPM, it's ready to fly.

Always lean a pumped engine as much as possible without RPM drop or detonation and leave the needle there. Do not lean to peak and then richen. When you fly, you must carefully listen to the engine and observe its performance. You may need to richen or lean the engine a bit, depending upon what is needed in flight.