I HAVE BEEN TOLD BY MY DEALER THAT IS TAKES TEN HOURS TO BREAK A MOTOR IN, I ALSO READ IN A MANUAL FOR A 1984 9.8 MERC THAT IT TAKES ONLY ONE HOUR.<br /><br />ALSO YOU ARE NOT SUPPOSE TO LET IS IDLE AND YOU ARE SUPPOSED TO VARY THE RPMS, AND NOT DO FULL THROTTLE AND RUN DOUBLE THE REGULAR OIL...