Before I go try it, is it necessary to replace both plugs after flooding the engine, or will just one clean one fire the
mixture off and have the second one clean just a few cycles later?

 

Remove the plugs and let them dry out. With a large fire bottle (CO2) with the pin pulled at the ready and the aircraft well clear of any buildings. Disable the ignition and fuel supply (pump or injectors).

With the throttle wide open and an assistant standing by on the fire bottle, spin up the engine for 15 seconds. Squirt some motor oil into the leading plug hole. Reinstall the plugs and attempt to start the engine. Your assistant should direct his or her attention to the exhaust system where the excess fuel will now be hiding.

 

The excess fuel will have removed any oil from the chambers, and compression will be poor. Thus the oil squirted into the engine. The engine will start sooner if the throttle is cracked a bit to assure cylinder filling and thus higher heat of compression. 

Always a trained hand on the throttle when attempting a start. Go to 2,000 RPM on the start so as to expel the flaming fuel and provide a really nice wind to clear away any problems below the aircraft. Same as starting a radial except for the RPM.

Chocks in and brakes on.

Lynn E. Hanover

AO-3 Plane captain

US Navy