How to read your outboard or sterndrive model and serial number
Short answer: The model and serial number are on an ID tag on the engine itself, usually on the mounting (transom or swivel) bracket of an outboard, or on the engine block or flame arrester cover of a sterndrive. The hull identification number (HIN) on the boat's transom identifies the boat, not the engine, so it won't tell you which parts fit.
Where is the tag on a Mercury outboard?
Mercury says that on outboards of 8 hp and up, the serial number tag is on the right (starboard) side of the transom bracket, about halfway down, below the powerhead. On 6 hp and smaller engines it's on top of the swivel bracket. You may need to tilt the engine up or turn it to see it.1 Mercury serial numbers are a number, a letter and six numbers, such as 0G112233.2
Where is it on a MerCruiser sterndrive?
Mercury says the MerCruiser serial number label is on the side of the engine or on top of the flame arrester cover.2 The drive (the part outside the transom) has its own serial number, so record both.
Where is it on Evinrude, Johnson and OMC engines?
On most Johnson and Evinrude outboards the ID tag is on the stern or swivel bracket that clamps to the transom. OMC Cobra sterndrives have separate tags for the engine and the drive. Record the whole model number, including the letters at the end, which usually mark the year and version.
Engine serial number vs hull identification number (HIN)
Federal rules require boats to carry a 12-character hull identification number, generally on the upper starboard corner of the transom.3 It identifies the hull and its builder. For engine parts, you need the engine's own model and serial number.
What if the tag is missing or unreadable?
Take clear photos of the engine from both sides, any casting numbers, and the part you're replacing. Parts on the engine often carry their own numbers, which can identify the model. Mercury also suggests keeping a photo of the tag on your phone in case it's damaged later.1
Why the exact number matters
Parts catalogs are organized by model and serial number range, and Mercury recommends searching its catalog by serial number to get the right parts.4 Two engines with the same horsepower can use different parts.
Common questions
Where is the serial number on a Mercury outboard?
On Mercury outboards of 8 hp and up, the serial number tag is on the starboard side of the transom bracket, about halfway down. On 6 hp and smaller, it's on top of the swivel bracket.
Is the HIN the same as the engine serial number?
No. The hull identification number identifies the boat and is usually on the upper starboard corner of the transom. The engine has its own model and serial number on its ID tag.
Where is the serial number on a MerCruiser?
Mercury says the MerCruiser serial number label is on the side of the engine or on top of the flame arrester cover. The sterndrive unit has its own serial number too.
Send your engine make, horsepower, year and the part you need (or a photo of the old part). The search is free, and you see a photo of the actual part before you pay anything.
Find My Part →Sources
- Mercury Marine, "How to Locate the Engine Serial Number on a Mercury Engine." mercurymarine.com
- Mercury Marine, "Owner's Manuals: Find Your Serial Number" (outboard and MerCruiser label locations). mercurymarine.com
- U.S. Code of Federal Regulations, 33 CFR Part 181, Subpart C, "Hull Identification Numbers." ecfr.gov
- Mercury Marine, Parts Catalog (search by serial number). Mercury parts catalog