What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Pilot and 2 passengers landed at Sunriver to refuel. Weather was 90 degrees f., light wind, airport elevation 4126. Refueled airplane up to 38 gallons total fuel, loaded 100 pounds baggage, and 3 men in aircraft of average weight. Engine runup fouled plugs and engine quit during pre-takeoff checks. Pilots leaned mixture to peak EGT and left mixture in that position for prolonged taxi to opposite end of runway to change direction of takeoff. Additional runup with mixture in peak EGT position performed, and shortfield takeoff executedon rwy 36 without ever adjusting mixture to full power. Pilot reports using 1/2 runway before breaking ground, and only gaining 50 to 100 feet altitude by end of runway. Second pilot privacy data omitted took over controls at trees at end of runway, and reported engine was loosing power. Airspeed dropped to stall speed and stall warning horn activated. Pilot privacy data omitted elected to land gear up in grass clearing directly off end of runway. Landing was successful, no injuries, minor damage to aircraft. Follow up planned for both pilots on density altitude and operation of fuel injection engine at high temperatures.
As the FAA filed it
(-23) PILOT AND 2 PASSENGERS LANDED AT SUNRIVER TO REFUEL. WEATHER WAS 90 DEGREES F., LIGHT WIND, AIRPORT ELEVATION 4126. REFUELED AIRPLANE UP TO 38 GALLONS TOTAL FUEL, LOADED 100 POUNDS BAGGAGE, AND 3 MEN IN AIRCRAFT OF AVERAGE WEIGHT. ENGINE RUNUP FOULED PLUGS AND ENGINE QUIT DURING PRE-TAKEOFF CHECKS. PILOTS LEANED MIXTURE TO PEAK EGT AND LEFT MIXTURE IN THAT POSITION FOR PROLONGED TAXI TO OPPOSITE END OF RUNWAY TO CHANGE DIRECTION OF TAKEOFF. ADDITIONAL RUNUP WITH MIXTURE IN PEAK EGT POSITION PERFORMED, AND SHORTFIELD TAKEOFF EXECUTEDON RWY 36 WITHOUT EVER ADJUSTING MIXTURE TO FULL POWER. PILOT REPORTS USING 1/2 RUNWAY BEFORE BREAKING GROUND, AND ONLY GAINING 50 TO 100 FEET ALTITUDE BY END OF RUNWAY. SECOND PILOT ^PRIVACY DATA OMITTED^ TOOK OVER CONTROLS AT TREES AT END OF RUNWAY, AND REPORTED ENGINE WAS LOOSING POWER. AIRSPEED DROPPED TO STALL SPEED AND STALL WARNING HORN ACTIVATED. PILOT ^PRIVACY DATA OMITTED^ ELECTED TO LAND GEAR UP IN GRASS CLEARING DIRECTLY OFF END OF RUNWAY. LANDING WAS SUCCESSFUL, NO INJURIES, MINOR DAMAGE TO AIRCRAFT. FOLLOW UP PLANNED FOR BOTH PILOTS ON DENSITY ALTITUDE AND OPERATION OF FUEL INJECTION ENGINE AT HIGH TEMPERATURES.