ENGINE and FRAME NUMBERS and other identifications

© Copyright, 2011, R. Fleischer

IDnumbrs.htm-67A
 

NOTE!!  BMW has, at times, used a quite different frame identification system for NON-U.S. motorcycles.  There may be a letter or two letters, followed by a serial number.  There may be a serial number followed by one extra number, and then the TYPE of motorcycle.   The first 7 digits for all types of these numberings, that I know of, are the serial number, and you can enter them into any serial number search. This means that if you have 8 digits at the beginning, 7 are used for the serial number.  I do NOT know what the letters nor the 8th digit means.     The following article applies to the North American shipments, and will also apply to wherever the 17 character VIN is in use, as far as I know.

In the OLD days, BMW simply used a serial number. Simple.  Find the number on the engine, find the frame number.  They may even have been the same number....usually were, actually....except a very long time ago.  For more information on the really old models, see Duane Ausherman's website.

In 1980, the VIN system was begun. This was, and remains, a 17 character Vehicle Identification Number (VIN), which is a combination of letters and numbers. At first, BMW matched the serial numbers of frame and engine. 1980 was the transition year, and some anomalies for 1980-1981 production are around, so if you have a production year 1980-1981, do not be upset if things seem strange. At the end of 1983, with the introduction of the 1984 model year bikes, BMW decided not to match up these numbers. They said so officially, so if YOUR numbers DO match, don't blame me!  Not only that, but BMW phased in something new....they were NO LONGER stamping the engine serial numbers next to the dipstick.  You can see that on 1984 and later.

Frame numbers were stamped at the steering head to 1982, then onto the frame below the right cylinder. Early bikes will usually have a frame number on a tag in the steering head area.   Engine numbers up to and well into 1983 were generally next to the dipstick.  After the 1983 model year, and this was phased in, they MIGHT have moved to a milled engine pad, where any engine number MIGHT not be even the same system, IF THERE, as previously.  Confused?  Well, BMW put some weird stuff on that milled area.     On that engine pad, sometimes the pad was missing!...were lots more characters identifying more things, some not revealed to me nor anyone outside the factory.  All that being said, some bikes don't conform to the published standards (yes, I have BMW's internal factory sheet on the milled pad area...but NOT how to interpret the second line on that pad...secret stuff!), limited as they are, for that engine pad....so, read on...

SO....BMW has not held itself strictly to its bulletins (Service Information, or SI) on these matters, so one may well see some combinations or variances. 

On models with a VIN, that number is probably; but may not be, all there, or is on the steering head, or partially there, on some 1980-1982 calendar models.  Where they are fully there, you will find all 17 characters (ALWAYS 17), on your lower right side frame tubing, roughly in line with the right side carburetor. Again, the transition period was mostly ending by 1982, after which the frame fully complied, always (AFAIK!)...and you may even find yours on the steering head area plate/tag.   You may also find it on a metalized tag on top of the driveshaft housing...which may not agree in ONE letter ID (year); and, you may have other funny things going on.

 In general, the VIN on the metalized tag on the driveshaft housing will agree with the VIN on the steering head or lower right frame. In a FEW cases, there may be a single LETTER difference. That letter is the YEAR identification letter. An example might be a late 1983-built RT. The UNofficial information ... is that BMW did not submit this end of production 1983 early enough for California smog testing. So BMW cleverly put a letter (E) in the VIN number on that driveshaft label showing it as a 1984, so it passes the smog requirements, yet the FRAME number, the number that is "official" for registration, has the letter (D) showing a 1983 model.  Naturally, the dipstick area DOES have the 7 digit serial number.  In every instance I personally know about, for this particular weirdness, the dipstick serial number is the SAME as on frame and tag.  The actual facts on this discrepancy are not known 100% for sure by me.  But, it does lend itself to folks possibly registering/titling a bike for either year.  The actual month and year of production are easy to find out from the last 7 digits on these models.  In fact, the last 8 characters will identify any vehicle for date of manufacture...and often, as in our Airheads, one needs only the last 7 digits.  

On many models you may find a set of characters stamped on that mentioned flat boss area of the crankcase, left front side above the frame tubing. These are a combination of letters and numbers that signify the model year, the week of (engine??) production, a sequencing number, and some Environmental Protection Agency [EPA] identification coding on the bottom line. If you have this set of characters and they match an engine serial number (which may or may not be at the old place, next to the oil dipstick...THAT was dropped too), hey, you have a strange one. 

Re: the flat boss area:
The top line will have something like (yes, this is from an actual bike)
83 23 2175
That is supposed to mean that the engine is an 83 model, produced in the 23rd week, and has a sequence code of 2175.  BMW issued a SI,  November of 1983, Bulletin No.:  11 025 83 (2088)... implying, but not specifically stating, that these things will identify the bike, for police or other reasons.   BMW stated that the machined surface on the crankcase will be located on the forward lower left side of the engine, below the exhaust pipe and frame tubing, and are two levels of stampings...that means two lines.   Do not count on that 23rd week as being when your bike was actually produced. Chances are pretty good your bike was assembled later. Also do not try to apply mathematics to the serial number range of total production you may find posted here and there for your year and model, you will probably get more confused, it probably will not correlate.

The Elves at BMW know, and they don't talk much. To me.

Under the above may be a line, perhaps something like:
DBM098042A3
That is some sort of certification coding. If you find out how to decode it reliably, let me know.  Supposedly it identifies the engine FAMILY, for certification purposes.

BMW has a SI Bulletin out on these things...well some of these things...and that SI I mentioned seems NOT to be entirely accurate. For example, the SI says that the week is listed first, and I am hard pressed to remember any year with 83 weeks. Since the Germans take a huge amount of time off for vacations and so on, and the factory shuts down for that every year, that might account for some of it (I am kidding here).  The SI also says that the certification coding is the same for all engines...it is supposed to be...meaning all R100 engines are one family code....... Suuuurrre it is! 
BMW specifically said that the second line (second level) is a requirement of the E.P.A. (Environmental Protection Agency), 'designated as required'.   I can't find out what that designation really is.  Perhaps YOU would like to research the EPA rules and find out for me!  riiiight!!!  

Further, BMW stated:   "All  identification numbers on the motorcycle, i.e., numbers for each motorcycle produced are recorded in our data processing equipment in our Factory.  Therefore, it is possible to assist law enforcement agencies or the National Automobile Theft Bureau for theft inquiries only.   This SI was for U.S.A. and Canada, ONLY

Some 1981 and 1982 bikes did NOT have the full VIN stamped onto the frame below the right cylinder. The Serial Number WAS there.   There may be a silver sticker there, the serial number being just forward.

You might find stamped serial numbers or sequence numbers on the transmission housing, inside area, or even to the left just barely below the aircleaner housing on 1984 and later transmissions.

If the flywheel is removed, the rear face of the engine is exposed, and you can see casting information stamped (cast-into) the area.  Typically there is a two digit number signifying the year of manufacture; and that number is surrounded by 1 to 12 raised dots.  These signify the production month of the CASTING.

Some engine blocks for replacement purposes were made without any serial number of the type normally seen on the pre-1984 models, that is, at the dipstick area.  The dealer was supposed to transfer (stamp into the metal) the old engine's number, and destroy the old engine and/or ship it to BMW (or Butler and Smith....which was the importer/distributor before BMWNA).  Some dealers did not apparently have metal punches and there are no serial numbers on those replacement engines.




OK, let us get to the final part of this posting, interpreting those 17 character VIN numbers. THIS you can trust (except for that one year anomaly I mentioned above, when you could have two years for the same bike)!!

I have BMW's own bulletin on this, so let's use it. It happens to correspond to what I know about vehicles, having been a paid part-time registration person for vehicles for a few years. 

 

NOTE:   BMW's own bulletin is titled:  Decipherment of BMW VIN's According to FMVSS 115.     The bulletin is clear enough, except for ONE THING!  There is an asterisk at the bottom of the bulletin. This is how that line reads:

*  Motorcycles produced before April 1/1981 have the letter "M".

BUT, the bulletin does not show another asterisk to show WHAT part of the VIN that applies to!   We shall have to ASSUME it applies to the TENTH character, the YEAR identification.

Another dealership bulletin said that for 1981 the number near the oil filler plug and for steering head is NOT the OFFICIAL ID.    You might as well forget all that....appears to me that no one paid the slightest attention.

 Here is a sample, for a R65:

The R65: WB10 364 0 4 B 6 385 003 
{the actual VIN would not have spaces}
 

 Here was my own 1983 R100RT:

The R100RT: WB10 449 0 9 D 6 243 160
{the actual VIN would not have spaces}


Now, let us take those VIN codes in order from the left:

W means that the manufacturer was In Europe.
    Combined with the B, it means BMW-AG, Munich, West Germany.

1 means motorcycle.
0 means a two wheel motorcycle (yeah, yeah, I know...).

((so you think your Harley was shipped by the factory as a trike or sidecar unit....better LOOK))

NOTE: BMW may, in parts list and other places, show a MODEL CODE as 364 (that  is R65) and 449 (that is R100RT).  They MIGHT have a zero in front of that number.  Confused about just that maybe zero?  

Going onwards with the decoding, after the 0 meaning a two wheel motorcycle:
the 3...or the 4 as shown for the two bikes above, identifies the LINE type. 
In the case of the R65, the line type for a 3 is 248/1. 
In the case of the R100RT, the line type for a 4 is 449 ??...naw, it is 247.  Confused?
Basically, just forget these particular Identifications.   For the nerdy, the R45/R65 bikes have a different line number, and all the big bore bikes have the same other number.  Are you confused more?

You are a Member of a Club that states in its purposes, club membership is for the 247 type...are you confused?   That's because of how the club bylaws were original stated. 
 

Continuing...

6 (R65) identifies the engine type, that is, number of cylinders, whether gasoline or diesel, and the size of the engine, and if 2 or 4 stroke. It is a BMW in-house coding.

The next digit, for the R65, a 4, is the NET horsepower.  In this instance, the 4 stands for 45 BHP. Astute observers may notice that in the R100RT the claimed horsepower by this coding is 90 or more. yeah, riiiight!

The following 0 had no meaning, that is, it was there and had no special meaning on my version of the BMW SI.

Next comes the 9th character, a check digit, the 4 in the case of the R65, the 9 in the case of the R100RT. Check digits have many uses, primarily it is a digit to tell a computer if things are possibly wrong in the rest of the sequence of characters.  If you REALLY are nerdy enough to want to know how to interpret check digits...or how they are determined, see http://www.vinguard.org/vin.htm         Warning, that is NERDY!

To save you all that trouble, and simplify the check digit, the check digit is a mathematically calculated value, calculated from the VIN position, an assigned code value, weight, and other things.  Whatever results they get from that, they divide by 11.  That becomes the check digit.  If the result turns out to be a 10, then the check digit is a character:  X                    Don't you feel clever now?

Next in the VIN is the letter identifying the PRODUCTION, NOT NECESSARILY CALENDAR year, and this is always in 10th position:

Notice the B in 10th position for the R65, and D in 10th position for the R100RT.  That letter is a YEAR code. This system is for U.S. production, that began in 1980.  
Officially, according to the adopted International Standards for official VIN 17 character numbers, the 11th position, in the examples, this is a "6", it is to identify the assembly plant.   



Note my prior information about an "M".....which I will repeat here:

NOTE:   BMW's own bulletin is titled:  Decipherment of BMW VIN's According to FMVSS 115.     The bulletin is clear enough, except for ONE THING!  There is an asterisk at the bottom of the bulletin. This is how that line reads:

*  Motorcycles produced before April 1/1981 have the letter "M".

((note from Snowbum:  BMW said all that, but I have never seen the anomaly...but, frankly, never have LOOKED for it either!))
 


OK...here is how the PRODUCTION year is identified:


1980 bikes used A                     NOTE THAT IN ALL INSTANCES 'bikes' HERE MEANS ANY VEHICLE.
1981 bikes used B
1982 bikes used C
1983 bikes used D
1984 bikes used E
1985 bikes used F
1986 bikes used G
1987 bikes used H
1988 bikes used J
1989 bikes used K
1990 bikes used L
1991 bikes used M
1992 bikes used N
1993 bikes used P
1994 bikes used R
1995 (last of airheads)...S
1996 bikes used T
1997 bikes used V
1998 bikes used W
1999 bikes used X
2000 bikes used Y
2001 to 2009 use digits 1-9
After 2009 the letters A, B, C, etc. will be used, in order of position in the alphabet.

Letters I, O, and Q are NOT use in the VIN number.
Letters U, Z, and the numeral 0 are NOT used in the YEARS position of the VIN.

 

NOTE!!...This page is concerned primarily with AIRHEADS....not other BMW models.   I know of instances where K bikes were made in June of 1992, and were 1993 official model year bikes.  Still, the information on this page is useful for ALL vehicles...including your cars and trucks.


Lastly, how to explain the official sequence number, which you might as well call the serial number, because that is what it REALLY WAS, a long time ago. You might even find that sequence (serial) number next to your dipstick, and agreeing with the frame number.   BUT, when the dipstick serial number was dropped, in 1984, the only serial, well, sequence serial, and I am NOT totally sure it really is a serial....appears to be more of a series sequencing, with jumps for production changes.
So, only BMW seems to know how to correlate engines-to-frames, AFTER the dipstick serial was eliminated...and there MAY be some other foolery too.



For a quick way of determining, on many models and especially later years, the manufacturing model year (I have seen this return errors once in awhile):
http://www.bmw-z1.com/VIN/VINdecode-e.cgi

Here is another website URL, which you may prefer, which uses a different chart format for serial/VIN's:
    http://bmbikes.co.uk/enginechassis.htm

 

For vastly more than you wanted to know about VIN numbers, as if this article was not nerdy enough:
http://www.vinguard.org/vin.htm


ADDENDUM #1

This section was added in late August, 2011, because of an inquiry I had over identifying an Airhead that had peculiar information from a seller to a potential buyer; and, the serial number was confusing.
I have edited my reply, and listed the questions I had for the potential buyer.  These are typical of some of the things that can help identify a 'peculiar' situation:

1.  Does the engine have a serial number located stamped into the boss that the oil dipstick screws into? ____________.   That can help determine the transition between 1983-1984; and also if the block was a replacement type (LOTS of years).
2.  Does the bike have a rectangular airbox? _____________.
     If the answer is YES, then squat down and look under the LEFT air tube coming out of the rectangular airbox, just barely under it MAY be a stamped number, possibly prefixed by one or two alphabetical  letters.  If so, what is that number?:__________.  That can help identify
     the transmission.
3.  The RIGHT lower frame tube should have a STAMPED 17 character VIN number in it.  That stamping is usually located on the frame tube directly below the right carburetor.  It is on the frame right at the rear motor mount. _______________.
     The 17 character VIN will identify the frame, and likely the bike.
     Some foreign-shipped bikes had a serial, not a 17 character VIN number there, and the serial may be 'funny'....it could have letters in front, or, nearly anything weird.
4.  You may have a large silver tag on top of the driveshaft tube.  If so, it will probably have the 17 character VIN number. _________________.  Some 1983-1984 bikes' VIN numbers will NOT agree, for the letter identifying the year (D, E) between that tag
     and the frame VIN.   Was mostly due to complications over getting the bike into sales, versus California smog certification time restraints.
5.  Below the LEFT cylinder MAY be a machined boss, with various things stamped into it.   I'd want to know exactly how that is stamped, both top line and lower line.
      __________________
      __________________

6.  Does the bike have snowflake wheels? ________ Front wheel size?_______; Rear wheel size? _________.  If not snowflakes, then what?  Describe them.
7.  What are the numbers stamped into the top front area of the REAR DRIVE___________.   Is the rear drive a MONO or a Paralever? ____________.
8.  Does the bike have a BMW FACTORY fairing or flyscreen?  RS style? RT style?   S style?  OR?................ If the bike has a factory fairing or flyscreen what type, and what is its COLOR ______________
9.   What does the three digit tag under the seat (typically on top of the rear fender) have printed on it:  __________
10.  Does the seller's title or registration call out "RS" (especially is this a California bike?)_____________________.  In California, and likely elsewhere's, the "RS" does NOT mean BMW RS.
11.  ANYthing you can think of that might help me determine what this bike REALLY is.
12.  Anything strange about the bike you have not yet mentioned?

 

 


 

Revisions:
02/13/2006:  minor updates, and also changed the BMBIKES.co.uk URL.
11/27/2007:  change to 67A from 67
01/10/2009:  Update with information to cover all vehicles; extend years/chart information; clarify a number of
                    items.  Incorporate finer details.  There were NO errors previously.
04/19/2011:  Add information (from my MODELS article) on engine casting numbers as seen near the crankshaft output; and on replacement blocks.
06/11/2011:  Clean up article.  Then mess it up by incorporating every anomaly I know about, then clean it a bit more.  All done at various times today.  Final release was 1015 hours Pcst.
06/11/2011:  Another small change. 
08/26/2011:  Add section Addendum #1
 

 

© Copyright, 2011, R. Fleischer

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