PRIOR TO THIS FLT, THE ACFT HAD NOT BEEN FLOWN FOR TWO MONTHS OR REFUELED IN FIVE MONTHS. DURING THAT PERIOD, IT HAD BEEN EXPOSED TO UNUSUALLY HEAVY AMOUNTS OF RAINFALL. AN ANNUAL INSPECTION HAD BEEN COMPLETED ON 1/12/82 & 77 HRS HAD BEEN FLOWN SINCE THAT TIME. ON 3/17/83, THE ACFT HAD BEEN TAXIED FROM ITS TIE-DOWN TO A MAINTENANCE FACILITY FOR ANOTHER ANNUAL INSPECTION. ON THE DAY OF THE ACCIDENT, IT HAD NOT BEEN RETURNED TO SERVICE SINCE THE FACILITY HAD FOUND WATER IN THE FUEL FILTER & CARB, AND HAD PLANNED TO TROUBLESHOOT THE FUEL SYS. THE OWNER ASSUMED THAT THE ANNUAL INSPECTION WAS COMPLETE SINCE HE HAD RECEIVED AN INVOICE FOR THE SERVICE. DURING A PREFLIGHT, HE DRAINED THE SUMPS. SOME WATER WAS FOUND, BUT THE SUMPS WERE DRAINED UNTIL ONLY FUEL FLOWED. DURING TAKEOFF, THE ENG LOST POWER AT APRX 200 FT AGL & WOULD NOT RESTART. THE ACFT COLLIDED WITH TREES & CRASHED DURING A FORCED LANDING. WATER WAS FOUND IN THE CARB, FUEL SELECTOR & STRAINER, & LEFT TANK. ALSO, THE O-RINGS IN THE FUEL CAPS WERE WORN.