How to Find Your Engine's Serial Number, Model and Year (and Get the Official Manual)

Mercury says to turn the outboard all the way to port, tilt it up, and look on the starboard side of the transom (clamp) bracket, about halfway down. The serial number has a number, a letter and six numbers (for example 0G112233). The label also shows the model and horsepower. On the latest labels, Mercury says a two-digit number in a box at the lower right is the year the outboard was built (for example "10" for 2010).

Some older Mariner outboards were built in Japan and use a different format, with a model code in front of the serial (owners often see codes like "6E9"). A Mercury dealer can match these to a model year and the right service manual.

The engine's label is on the side of the engine or on top of the flame arrester cover, according to Mercury's manual instructions. The transom assembly and the drive carry their own labels or stamped numbers. Note each one separately.

Look for the serial number label on the clamp/swivel bracket. Yamaha's manual lookup asks for the Primary ID, which has three parts: the prefix model code, the shaft length and the serial number. All three are on the label and on your warranty card. Yamaha notes that older engines may not show leading zeros, but you must type them in.

The serial label is on the clamp bracket. Suzuki's Technical Manual Library lets you filter by engine model (for example DF140B), engine prefix and serial number; together the prefix and serial make up the full number on the label. The matching row shows which owner's and service manual covers your serial range.

Honda says the model name is on the engine cover sticker; every Honda model starts with "BF", but those two letters don't appear on the sticker. The frame serial number is stamped into a metal plate on or near the stern bracket, in the form "BXXX-XXXXXXX". Honda also calls it the product identification number.

The model and horsepower are on the serial label on the clamp bracket (the cover photo of this guide shows one). Tohatsu's manual page is sorted by horsepower (and by kW output for electric models), so the model code and horsepower are what you need. Many older Nissan outboards were built by Tohatsu; a Tohatsu dealer can confirm the match from the serial number.

The model and serial number are on a label on the swivel or clamp bracket. Evinrude Operator's Guides are on BRP's Operator's Guides site: choose Evinrude, then the folder that matches the letter code in your model number (newer guides are grouped as "AG Models," "AH Models" and so on, then by E-TEC or E-TEC G2 and horsepower), or the model year for 2004 to 2012 engines. The Johnson section there only covers 2004 to 2007. BRP stopped building Evinrude outboards in 2020, so for older Johnson/OMC engines, or if your guide isn't listed, ask an Evinrude service dealer.

Volvo Penta engines have an identification decal on the engine, and the drive has its own. Volvo Penta's support site searches manuals by product designation (for example D2-40 or V8-350) or by serial number. Some documents need a free Volvo Penta Connect account.

Diesel engines usually carry a nameplate on the engine itself, often on top of the engine or on the valve (rocker) cover. You need the exact model (for example 3YM30AE or 4JH45) and the serial number. Yanmar's own FAQ says the serial number is on the engine information plate and that the engine model name (such as 4JH3 or 6LY2) should always go with it; the Operation Manual for current engines is on each engine's page on Yanmar's site, and for older engines Yanmar points owners to a dealer or distributor. If the plate is painted over or missing, a dealer can often find a number stamped into the block. The manual finder also covers Cummins, Caterpillar, Westerbeke, Beta Marine and other diesel makers.

On a PWC the HIN is on the back of the hull, and it is what most PWC makers use to look up the model and year. The engine has its own serial number, which Sea-Doo recommends recording in the Operator's Guide. Kawasaki and Yamaha WaveRunner manual lookups also go by model, year or HIN.

Clean a dirty label gently with a damp rag; don't scrub, or the print can wipe off. Take a clear photo of every label. Copy the numbers exactly: watch for 0 vs O, 1 vs I, 8 vs B and 5 vs S. Save the photo and the numbers in your BoatMend boat profile so you never have to tilt the engine to find them again.

Some labels show the model year or a production date (like the year box on newer Mercury labels); many don't. Don't assume the boat's model year from the HIN applies to the engine: engines are often older or newer than the hull, or replaced. If the label doesn't say, an authorized dealer for your brand can look up the year from the serial number, and some manufacturer lookups (like Suzuki's serial-range table) narrow it down.

Open the BoatMend manual finder, pick your engine brand, and follow the link to the maker's official owner's manual page with your model and serial number in hand. Most owner's manuals are free (Mercury, Yamaha, Suzuki, Honda, Tohatsu); a few brands only sell printed copies. BoatMend never hosts the manufacturers' manuals itself; it sends you to the official source.

Check your paperwork, then ask a dealer: many engines also have numbers stamped on the block or bracket, and dealers know where. If you are buying a used boat and the engine's ID labels and stamped numbers have been removed or altered, be very careful: it can be a sign of a stolen engine. Ask for proof of ownership before you buy.