Most riders and vehicle owners alike are familiar with a Vehicle Identification Number (VIN), but not everyone is as familiar with a motorcycle’s engine number.
Like the VIN, the engine number is a unique sequence of letters and numbers stamped onto the engine at the factory.
On this page, we’ll cover exactly what an engine number is, where to find it on your motorcycle, and what you may need it for.
Where to Find a Motorcycle Engine Number
The exact location of a motorcycle’s engine number will vary slightly from manufacturer to manufacturer.
While a VIN can be found in a variety of locations on your bike, the engine number is usually included on only one spot on the engine.
On pretty much every motorcycle you’ll find your engine number stamped or etched somewhere on the engine cases.
On many bikes, there will be a distinctive rectangular area where the engine number can be found.
The most common places to look for this on your engine include:
- On the left or right side of the crankcase cover.
- Near the oil sight hole on the engine case.
- On the cylinder head.
- Towards the top of the crankcase right below the cylinders.
- On the front or rear of the crankcase.
- On the bottom of the crankcase near the swingarm, side stand, or footrest.
Additionally, depending on the state where the bike was purchased or last registered, you may be able to find the engine number on the MCO, certificate of title, or Bill of Sale.
Can’t Find your Engine Number
If you’re having trouble finding the engine number, the tips below can help.
First, check your owner’s manual. There is often a section about where the different numbers and codes can be found on the bike.
Next, when you’re checking around the engine, look near the seams of the crankcases and cylinder heads. While the engine number may be harder to see on certain bikes, they should be at least reasonably visible.
Note that certain bikes may require you to remove fairings or side covers to get to where the engine number is stamped.
Finally, be aware that the engine number may be covered in a thick layer of grime, dirt, and grease. This is often the case for engine numbers stamped on the bottom or towards the rear of the crankcases.
What is the Engine Number?
Like the VIN, the engine number is a unique identifier assigned at the factory to a motorcycle’s engine.
The number will contain information including:
- The motorcycle model.
- The engine specs and production series.
- The sequential order in which a particular engine was produced.
How to Read an Engine Number
Each motorcycle manufacturer may have a slightly different method for assigning engine numbers.
In most cases, the engine number will be assigned a prefix that denotes the model of the bike.
Next, the engine number will be assigned based on engine type, model year, and production series.
Is the Engine Number the same as the Motorcycle’s VIN?
No, the engine number is not the same as the motorcycle VIN.
The VIN (Vehicle Identification Number) is the 17-digit code stamped in a few different locations on the bike.
Should the Engine Number Match the Frame Number?
On certain makes, models, and model years, the engine numbers and the frame numbers actually do match.
In those cases, a mismatched engine and frame number would tell you that the engine had been replaced at some point in the motorcycle’s history.
However, this is not the case for every motorcycle.
When You May Need the Engine Number
One of the primary reasons you would need your motorcycle’s engine number is when you need to order replacement parts for the engine.
In these cases, you’d be able to provide the manufacturer or dealership with your bike’s engine number to be sure that you’re getting the right parts for your specific engine. That’s important if you’re planning on rebuilding the engine.
Since engine designs vary and change over time, the engine number is also useful for when the manufacturer needs to issue recalls or service bulletins.
In some states, the engine number is also required in order to title and register the bike.
In states that require it, the engine number will be listed on documents like the title and bill of sale.
If you were to change the motorcycle’s engine in the future, you would need to update your records with the DMV.