Do frame and engine numbers need to match?
This is a question we are asked regularly.
The answer depends on the make, model and age of the motorcycle.
Many older motorcycles have had engine changes during their lifetime and it is not unusual to find a motorcycle with a replacement engine.
In many cases the frame number is the primary identifier used for registration purposes.
If you are buying a classic motorcycle, it is worth understanding what numbers are present and how they relate to the motorcycle's history.