Outboard boat engines, much like automobiles, have serial numbers assigned to them after production. Each engine maker uses a different placement point for these numbers and also use a different code to interpret the alpha-numeric cipher. To find the serial numbers on outboard engines, you need to search the shaft of the engine and under the cowling---the cover that rests over the engine itself.
Pull the boat's shaft up and out of the water using either the power lift assist or by grabbing the cowling handle and lifting up and back toward the boat.
Inspect the entire shaft looking for a small set of etched numbers and letters or for a small metal plate riveted to the shaft. This is the boat engine's serial number. Write down this number, or take a picture of it using the digital camera.
Open the engine's cowling and look at the engine block or on the inside of the cowling for the serial number if it's not on the shaft.
Determine the make of the engine by looking for a name such as Mercury, Evinrude or Johnson, to name but a few.
Go to a boat-engine website; examples of this include nauticexpo.com or boat-links.com. Go to the engine maker's website from these lists. Follow the links at the proprietary engine maker's site to find the serial number identification code legend. For example, Johnson Motors codes read something like this: J33ELUTa. The "E" means it is an electric start engine, the "J" identifies it as a Johnson, and the "33" means the engine has 33 horsepower. Each maker uses a different code.
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