• Vehicle Identification Numbers (VIN) have changed over the years for the sake of theft deterrent and inventory. Modern VINs have Government mandated information as well as an individual (one only) number that pertains to one certain bike. Policy, parts and service have been issued by the MoCo based on these numbers as well. For instance, an upgraded part may be substituted for all future use at the local dealership by communication from the MoCo as in, “Use this new part number instead of the original part for all future models beginning with engine serial number 45678”. There are likely many other uses and reasons for the distinction changes in the VIN also. Below is a list of changes in the VIN and how to decipher them.
• A VIN isn't cut and dried as some guys perpetuate it to be. There are circumstances when a VIN number can be legally re-applied to a later motor by the owner if he is fixing his bike legally. Once he gets signed off by the authorities, he is under no obligation to retain the original VIN stampings. So, when he sells that bike with the later motor with the home stamped early serials he has obeyed the law, and the bike is legal. Back in the day, it was very common to see KH bikes with new XL factory motors carrying the orig KH numbers. ¹⁾
• Preserving your VIN while painting / powder coating frame. Leave a small area with the numbers bare and mask the numbers before painting the frame. Pulled the tape off when done and apply a clear coat over the frame and the small bare area with the numbers. Not too noticeable and you will be able to see the frame numbers. ²⁾

• In 1957, the Engine Serial number was simply stamped, starting with the first four digits, into the left side crankcase with the year and bike model followed by a series of 4 or 5 numbers that established the individual serial number for each bike. The bike models are abbreviated with the denotation for a standard Sportster being (XL). In theory, the MoCo should know everything that was installed on each individual bike as it left the factory right down to the paint color. But records are scarce the farther you go back it seems.

• From 1962–1969, the Engine Serial numbering was the same as before with an added twist. Models with 4 digit production (serial) numbers have an even-numbered first digit for even years and odd numbered first digit for odd years. Models containing a 5 digit production number will have the first two digits even for even years and odd for odd years. ³⁾
  • If the engine# does not follow this even or odd numbering sequence, you can almost guarantee that the number has been altered. It is extremely common to find mismatched engines in these early bikes with different engine numbers than the title paperwork. ⁴⁾
• The first engine# of a new pre - '62 model year was, for instance 66XLCH1001 (if the first model stamped of that year were to be a Sportster..and a XLCH). All 1969 and earlier model year engine#s all have a minimum of 4 sequence numbers. These #'s were stamped sequentially regardless of model. For example it is possible to see 66XLCH4996, and then see 66FLH4997. Although the engines were made in batches, so in this theoretical instance the XL would have been the last of a batch, and the FL engine being the first of a batch. ⁵⁾
• The first engine# of a '62-'69 model, all else the same would be something like this:
  • For the first 1962 XLCH - 62XLCH2001 ⁶⁾
  • For the first 1963 XLCH - 63XLCH1001 ⁷⁾
• For matching serial numbers against number of bikes sold that year:
  • 68XLCH14001 would be bike production number <6001 ⁸⁾

Examples of Good and Bad Serial Numbers ('62-'69)

Engine #s for 1957-1969 Models (motor numbers only)
Model Year (first 2 digits)	Model (next 2 digits) (up to 4)	Sequential Serial# (remaining digits)
(example) 57	XL XLH XLC XLCH XLRTT XLR	(example) 12345
Example: (57XL 12345) indicates a 1957 XL model and is stamped on Left Engine Case Between the Cylinders 10)
Example VIN Reads
57	XL	12345

• A new numbering system (first year referred to as a Vehicle Identification Number or VIN). The same VIN is stamped into both the engine and frame. It consists of a model code, a serial number, a manufacturer's identification, and the model year. The serial number is the 3rd through 7th digit of the VIN. All serial numbers run consecutively regardless of model year. ¹¹⁾
• The only legal VIN number for Harley’s produced from 1970 and up is on the frame. It doesn’t matter if the engine case number matches your registration papers or not, if the frame VIN doesn’t match the registration, it's not legal. It also should be noted that any alteration to the VIN is illegal. This goes for re-stamping frames or adding the original VIN to a replacement frame. If you replace the frame, you need to have a new VIN assigned to your Harley. ¹²⁾
• Starting with the 1970 season, the Vehicle Identification Number (VIN) is stamped on the right side of the engine crankcase between the cylinders (except '70-E'71 - see below) and on the right down tube below the neck ¹³⁾. In addition to these numbers, an identification label is located on the frame below the stamped VIN ¹⁴⁾ giving the VIN and date of manufacture. This label was required by law for identification.¹⁵⁾ However, the only legal VIN acknowledge by the law (1970 and up) is the one stamped on the frame.
• However, 1970 is a one year engine with exception of some early 1971 models with cases carried over from the 1970 batch. The VIN pad is in a different position from every other year which is between the front two lifters. 1970 was the last “pre nose cone” engine (Flatside ?). 1970 frame is one year as well, but the later cam covers and rockers can be substituted so you can't be sure what you have just by a casual glance. ¹⁶⁾
• Early 1971 models with the 1970 cases didn't have the star cast before and aft of the VIN but the frame did have them. ¹⁷⁾
• Not all 70 or e71 had motor or frame stars, but all 71s did have the frame stamped though. Some 1970 frames were bare. ¹⁸⁾

VIN for 1970-1978 Models
Sportster Model Code (first 2 digits)	Serial Number (next 5 digits)	Manufacturer (second to last digit)	Model Year (last digit)
3A - XLH 4A - XLCH 2G - XLT 9B - XLRTT 1C - XR-750 4D - XLA 7F - XLCR 4E - XLS	Starting from 10,000 and up	H = Harley Davidson	0 - 1970 1 - 1971 2 - 1972 3 - 1973 4 - 1974 5 - 1975 6 - 1976 7 - 1977 8 - 1978
Example: (4A13675H0) indicates a 1970 XLCH and is stamped on the right side engine case and on the frame with the addition of a label on the steering head showing the VIN and date of manufacture. 19)
Example VIN Reads
4A	13675	H	0

• Just as in '70-'78, the Vehicle Identification Number (VIN) is stamped on the right side of the engine crankcase and on the right down tube below the neck. ²⁰⁾ In addition to these numbers, an identification label is located on the frame below the stamped VIN ²¹⁾ giving the VIN and date of manufacture.
• 1979 Exception: Click here to download/view Service Letter ML-110
  • For a period of one month from January 9 to February 8, 1979, (1200, 1340 and 1000cc) motorcycles were produced with the crankcase number stamped on the engine number pad instead of the VIN (frame) number in this location. This change was introduced to allow replacing engines in motorcycles at the factory without the cumbersome - and within some states - illegal re-stamping of the original VIN on the replacement engine crankcase pad. ²²⁾
    • Additionally, this change would have deterred organized theft rings because they would have no knowledge of the correct match-up of the frame VIN and the engine pad number. ²³⁾
  • Following this change, it was pointed out that the engine to frame numbering would have better traceability if the numbers matched. Also pointed out was that any deviation in characters or numbering would create suspicion from officials that the numbers may not be valid, indicating a stolen and/or renumbered engine. ²⁴⁾
    • Upon a considerable investigation and analysis, it was felt that the advantages of the old system out-weighed the advantages of the new system and it was decided to revert to the duplication of the engine and frame VIN numbers which had been in effect since 1970. ²⁵⁾
  • Motorcycles produced in which the engine pad numbers do not match the frame VIN's are: ²⁶⁾
    • Frame VIN 43000H9 to frame VIN 48199H9. ²⁷⁾
  • The frame (VIN) numbers for all VIN model prefixes within the above range are in numerical sequence; however, the engine pad numbers are mixed. ²⁸⁾
  • For the purpose of cross checking numbers, the correct VIN's and corres­ponding engine pad numbers were recorded on the retail sales and warranty registration information form F-314, mailed to the dealers when these motorcycles were shipped to them. ²⁹⁾
  • Also, the vehicle identification number records were maintaineded by the Highland Insurance Service at Harley-Davidson Motor Co., Inc. Milwaukee, Wisconsin 53201 and the National Automotive Theft Bureau divisional offices. ³⁰⁾
  • Regardless of the engine case number, the title must always match the frame VIN. ³¹⁾

VIN for 1979-1980 Models
Sportster Model (first 2 digits)	Serial Number (next 5 digits)	Manufacturer (2nd to last digit)	Model Season (last digit)
3A - XLH 4A - XLCH 4E - XLS	10,000 and up	H - (1979 HD) J - (1980 HD)	9 - (1979) 0 - (1980)
Example: (3A 11790 H9) indicates 1979 XLH, appearing on the engine right case and right side of steering head on the frame 32)
Example VIN Reads
3A	11790	H	9

• In 1981, the full VIN was expanded to include country of origin, maker, bike weight, engine displacement, introduction date, a check digit and which factory made it ³³⁾. The engine number was no longer stamped the same as the frame. An abbreviated version was stamped into the right side engine case which is the exact same as the frame numbers but certain designations were left out. including country of origin, maker, bike weight, intro date, check digit and plant of origin.
  • The new 17 digit Vehicle Identification Number(VIN) is used on all models including the Classic Sidecar. This new nationwide system is designed to provide improved theft protection and more specific vehicle information to Harley-Davidson Motor Co. Inc. and government agencies.
  • The full 17 digit VIN is stamped on the steering head and on a label located on the right front downtube. The abbreviated version consists of the model designation, engine displacement and model year codes followed by the serial number.
  • The number itself is different, but it's location didn't change from the previous year models.
• In April of 1981, the MoCo issued a service bulletin acknowledging that the “6” and “9” characters used in the stamping of engine and crankcase numbers could be interchanged. If that turned out to be the case on factory stamped numbers, this would still be a legitimate and acceptable number. Also included with this bulletin is a chart showing legitimate characters used for VINs by the MoCo. ³⁴⁾
• Early or Late 1984 Models cannot be deciphered from the VIN. You need to depend on the parts that are on it for that. For instance, look at the lower front of the engine. E84 has a generator, an unmistakable, easy to identify component. L84 should have an oil filter in the same location. ³⁵⁾
• In 1984, the right crankcase number (not to be confused as a VIN) moved to the lower face below the gear case (near and under #4 cam) on the outside of the engine. ³⁶⁾

17 Digit VIN for 1981-1985 Models
Origin	Make	Weight Class	Model	Engine Size	Intro Date / Special Models	VIN Check Digit	Model Year	Assembly Plant	Serial Number
1 = Made in USA	HD = Harley Davidson	1 = 1000cc	CA = XLH1000 CB = XLS1000 CC = XLX1000 CD = XR1000	H = 1000cc	1 = Regular 2 = Mid Year 3 = E1984	Can be 0 - 9 or X	B = 1981 C = 1982 D = 1983 E = 1984 F = 1985	Y = York, PA	6 Digits (varies)
Example: (1HD1CAH16BY112016) designates a 1981 XLH 1000, stamped on the steering head with a sticker VIN on the right front frame downtube. The abbreviated VIN appears on engine right case (CAHB 112016) 37)
Example VIN on Frame Reads
1	HD	1	CA	H	1	6	B	Y	112016
Example Abbreviated VIN on Case Reads
			CA	H			B		112016

Click on a pic to enlarge:

1964 XLCH Engine VIN 38)

1968 XLCH Engine VIN 39)

1968 XLCH Engine VIN 40)

1969 xlch vin 41)

Click on a pic to enlarge:

Early 1971 Factory Engine Identification Numbers 42)		1976 Factory Engine Identification Numbers 43)

Pics upside down to show numbers.

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If the VIN has been removed and painted over, the VIN panel may look smooth after grinding and painting. ⁴⁶⁾
It's pretty easy to coarse grind and then polish up a flat metal panel.
Sometimes previous owner's / builders could have bondo'd and painted over the VIN and it still be there under all the crap.

You can chemically strip the paint on the sides of the neck to keep from harming the metal and reveal previous metal work there.
Look for sanding or machining marks where the numbers should be.

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The VIN is factory stamped in the neck.
On 1994-1995 models, a VIN sticker is placed on the steering head.
On 1996 models, a VIN sticker is placed on the right downtube.

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The VIN is factory stamped in the steering head with a VIN sticker on the right downtube.

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The VIN is factory stamped in the steering head with a VIN sticker on the downtube.

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The VIN is factory stamped in the steering head with a VIN sticker on the downtube.

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The VIN is factory stamped in the steering head with a VIN sticker on the downtube.

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