Incident Summary
A pilot reported a loss of engine power approximately 50 minutes after switching from the right auxiliary fuel tank to the left auxiliary tank. The pilot had flown for 35 minutes using the right auxiliary tank before making the switch. Following the power loss, the pilot attempted engine restart procedures but was unsuccessful.
Pilot Actions
The pilot stated that after the engine lost power, he performed the restart procedures as outlined in the Pilot Operating Handbook (POH). Despite these efforts, the engine could not be restarted.
Aircraft Systems
The aircraft was equipped with two auxiliary fuel tanks, each holding 17 gallons. The POH notes that if the fuel line runs dry, the boost pump must be activated to purge air from the line. The engine driven fuel pump was found to have a leak in the high pressure adjustment screw O-ring. Additionally, the fuel pump was operating below the required fuel pressure limit specified in the POH.
Fuel Management
The POH specifies a fuel consumption rate of 14 gallons per hour at 75 percent power at 6,500 feet mean sea level. The pilot managed the fuel supply by initially using the right auxiliary tank for 35 minutes, then switching to the left auxiliary tank. The subsequent power loss occurred about 50 minutes after the switch.