THE ACFT MADE A HARD LANDING OFF THE RUNWAY ON AN AIRPORT DURING A FORCED LANDING. ACCORDING TO THE PILOT THE ACFT HAD JUST COME OUT OF ANNUAL INSPECTION AND IT WAS NOTED THAT THE FUEL SELECTOR VALVE HANDLE WAS BROKEN. A NEW VALVE WAS ORDERED AND A TEMPORARY HANDLE WAS PUT ON THE VALVE. DURING A RUN IN FLT ON MAY 3 THE ENGINE QUIT BUT THE PILOT WAS ABLETO LAND ON AN AIRPORT. THE PILOT CALLED HIS MECHANIC TO BRING FUEL AND THEY ADDED 5 GALLONS TO THE RIGHT TANK. THE PILOTWAS CONVINCED BY THE MECHANIC TO WAIT BEFORE FERRY OF THE ACFT WAS TO BE ACCOMPLISHED. THE PILOT CAME BACK THE NEXT DAY WITH 10 GALS OF FUEL AND STILL NOT KNOWING WHICH TANK THE SELECTOR WAS ON PUT 5 GALS IN EACH TANK. THIS MADE 10 GALS IN RT TANK AND 5 GALS IN THE LEFT. THE PILOT TOOK OFF AFTER CHECKING THE ENGINE AND 3 MINUTES LATER THE ENGINE QUIT. HE WASABLE TO LAND ADJACENT TO THE RUNWAY WHERE THE GEAR COLLAPSED. INVESTIGATION REVEALED THE SELECTOR WAS ON LEFT TANK. ONE AND ONE HALF GALS IN EACH TANK WAS UNUSABLE. THERE WAS ONLY A TRACE IN THE LEFT TANK AND APPROX 7 GALS IN THE RIGHT.