• Mercruiser uses serial numbers much more than model year designations, so a serial number is crucial to identifying the correct parts for your motor, transom or sterndrive

• For engine parts: The tag or plate with the engine serial number is located either near the starter by the flywheel housing OR on the rocker arm or flame arrestor cover

• For transom parts: The tag or plate with the transom serial number is located either on the inner transom plate inside the boat OR on the upper swivel pin

• For drive parts: The tag or plate with the drive serial number is located on the upper drive shaft housing on either of the sides of the housing OR on the back

• The early (beginning) product serial numbers were 7 digits. Example: 1234567
When MerCruiser reached serial number 9999999 they began using a number followed by a alpha character then 6 digits. Example: 0F382645

• Also helpful in identifying parts is knowledge of marine block manufacturer (Ford/GM), horsepower and year of manufacture, but serial number is always the best piece of information for MerCruiser products