Preflight the airplane and start the engine. Taxi the aircraft to the run-up area as determined or assigned by Ground Clearance at your airport. If your airport has no ground or tower, proceed according to the latest aviation chart or airport guide to the run-up.
Increase the throttle on the aircraft and apply both brakes according to the operations found on the checklists or the aircraft handbook.
Turn the ignition key one click counterclockwise to the "L" position and watch the RPM indicator. The RPM should drop a few rotations and the engine will change pitch slightly. This indicates a properly functioning magneto. Listen for stuttering or choppy engine action. This indicates there is carbon buildup that needs to be burned out. Keep the brakes applied and turn the key back to the original position. Increase the throttle to around 2300 RPM for 30 to 45 seconds to burn out the carbon. Reduce the throttle back to the magneto testing speed as indicated in the aircraft handbook.
Turn the ignition key two turns counterclockwise to "R." Watch for the decrease in RPM and listen for the change in engine pitch. If there is stuttering, go through the carbon burn off procedure again. Turn the key back to the original position.
Continue with the run-up check as indicated in your aircraft checklists and handbook.
