Vintage Norton Motorcycle Engine & Frame Serial Number Decoding.
Norton N15 750 twin N P11 750 twin P11 or 20 Jubilee 250 twin 17 All 650s 18 Naviator 350 twin 19 Atlas 750 twin 20 Early Commando 750 twin 20 MODEL IDENTIFICATION CODES Engine and Frame numbers are identical on all Norton motorcycles from 1946. All engine and frame numbers are prefixed by a letter and a number to identify the year of manufacture. Finally, adding the gearbox casting and serial number might give some info as well. I will add numbers to additional lists if it is useful. If you want to help unravel the past, please send me your frame and engine numbers (and preferably the others as well). 62801 / 69999 Model 18: Push-rod engine; Diamond frame; bore and stroke, 79 x 100. Model 19: Push-rod engine; Diamond frame; bore and stroke, 92 x 113, or 79 x 100. Model ES2: Push-rod engine; cradle frame; bore and stroke, 79 x 100. 70000 / Model 18: Eng.
For information about a specific make or model of a motorcycle, the owner must have the frame (chassis) and engine numbers. Unfortunately, different manufacturers use different numbering systems and often place the numbers in odd places.
Later motorcycles (post-70s) typically have a stick-on decal or plate on the headstock. Besides detailing the bike's engine and frame number, the decal will show the makers, the model and year of manufacture. However, the model information can be confusing as machines offered for sale after September (in the United States) will technically be the following year's model.
![Norton Engine Serial Numbers Norton Engine Serial Numbers](/uploads/1/2/5/3/125377183/749186518.jpg)
For example, a motorcycle with a year model stated as 10/1982 on the VIN (Vehicle Identification Number) decal will actually be a 1983 model.
Matching Numbers
Early motorcycles generally had the same number for the engine and frame (often referred to as matching). However, occasionally an engine case (containing the original number) may have been replaced due to damage and will not, therefore, have a number stamped on it. Alternatively, the owner may have stamped the new case to match the frame number; a practice that may be frowned upon, but if photographed and logged properly, will not greatly affect the value. (This is a typical example of when it is imperative to save the old parts.)
Locating Numbers
Locating a frame number on an early machine, especially one that is dirty and in need of restoration (barn fresh for example), can be challenging. However, typically, the number will be found in one of the following locations:
- Headstock (the most common location)
- Frame down tubes
- Lower frame rails (at the side)
- Stamped onto the plate that carries the swingarm pivot
- Under the gas tank on the frame's top tube
- Engine mounting plate (front or rear)
Engine numbers are generally stamped into aluminum cases. Scorpion saison 2 wikipedia. The location varies between manufacturers but will be located on the crankcases, just below the cylinder.
Help Through Clubs
Identifying a classic motorcycle from its frame and/or engine number is important for parts ordering or valuation purposes. Willing and able to help in this process are the many make specific clubs. In particular, the UK's Vintage Motorcycle Club Ltd. will undertake a search of any vintage motorcycle for a small fee (no charge if they cannot find the appropriate information).
Assuming the manufacturer is still in business, their websites are also a good source of information if the researcher is willing/able to spend time sifting through the various pages.
Norton Serial Number Lookup
Finally, a word of caution: a classic motorcycle may be listed in a sale as a particular year and model but the prospective purchaser must research the engine and frame numbers to ensure they match the claimed model a model year error, for instance, can make a big difference to the value of a motorcycle.