EMERGENCY
SPARK PLUG FOULING
Ignition Switch -- CHECK BOTH, L and R to identify ignition-related roughness.
Mixture -- LEAN to the recommended lean setting for cruising flight.
If roughness does not clear after several minutes -- TRY a richer mixture setting.
If roughness persists -- PROCEED to the nearest airport for repairs using BOTH unless extreme roughness dictates use of a single ignition position.
MAGNETO MALFUNCTION
Ignition Switch -- CHECK L and R to identify the malfunctioning magneto.
Power and Mixture -- ADJUST to determine whether continued operation on BOTH is possible.
If continued operation on BOTH is not possible -- SELECT the good magneto and PROCEED to the nearest airport for repairs.
ENGINE-DRIVEN FUEL PUMP FAILURE
Auxiliary Fuel Pump Switch (FUEL PUMP) -- ON.
Flight -- TERMINATE as soon as practical.
EXCESSIVE FUEL VAPOR INDICATIONS
Auxiliary Fuel Pump -- ON.
Mixture -- LEAN as required for smooth engine operation.
Fuel Selector -- SELECT another tank.
Airspeed -- INCREASE as practical to improve cooling airflow through the cowling.