THE PLT WAS MAKING HIS FIRST FLT IN HIS RECENTLY PURCHASED ACFT. THE PLT STATED THAT BOTH FUEL TANKS WERE FULL PRIOR TO TAKE-OFF. APPROXIMATELY 20 MINS AFTER TAKE-OFF, AN ATTEMPT WAS MADE TO SWITCH FROM THE RIGHT FUEL TANK TO THE LEFT FUEL TANK. SECONDS LATER, THE ENG LOST POWER & ALL ATTEMPTS TO RESTART THE ENG FAILED. AN EMERG DESCENT WAS ESTABLISHED & THEACFT CRASHED INTO A WOODED AREA. THE ACFT WAS DESTROYED & THE PLT & HIS PAX SUSTAINED MINOR INJURIES. THE ACFT HAD NOT BEEN FLOWN IN THE PAST 2 YEARS. THE PLT STATED THAT APRX ONEMONTH PRIOR TO THE ACCIDENT, HE HAD DRAINED APRX ONE PINT OFWATER FROM THE SINGLE DRAIN POINT IN THE FUEL SYST. ON THE DAY OF THE ACCIDENT, HE STATED THAT HE HAD DRAINED THE FUEL SUMP DURING THE PREFLT INSPECTION & DID NOT OBSERVE ANY WATER. ALTHOUGH BOTH FUEL TANKS RUPTERED ON IMPACT. AN EXAM OF THE LEFT TANK REVEALED THE PRESENCE OF WATER IN THE BOTTOM OF THE FUEL TANK.