The International CBX Owners Association

Bike A: Built in October 1978. Among the first 500 produced that month. Engine built September 28, 1978. 97th unit built that day
Bike B: December 1978, Middle of the month. Engine built December 8 1978, Unit #12

Both engines and frames original to each other (99.9%)

Mine has engine number 2002745 and vin ending 002445
Built 4/78

So, Ashish, you bought yours from Mike Kopec in Long Island....

Mike, What can you tell me about this motor. I found it at a M/C salvage yard in Houston,Tx about 12 or 13 years ago. Engine was complete but cam cover was off, motor had water damage. Did manage to find cam cover before I left. Can you tell what month was produced? I'm thinking was the 55th motor off the line.

EMS wrote: ↑

Sat Jul 18, 2020 11:35 am

So, Ashish, you bought yours from Mike Kopec in Long Island....

Hah ! Yes I did. Know the guy ? He has a beautiful cafe racer that he built. Unlucky for him, due to back issues he does not ride

That’s the bike he has

Jerome, I cannot make out the stamping on the motor as the picture is too small and it does not enlarge for me.
If the stampings say 53.3 ?? 55, it means the following:
53 - 1978
3 - March
?? - Day of the month
55 - 55th engine THAT DAY, not over all.
The engine would be worth conserving. I personally know of only 3 documented production motors with lower serial numbers, 61,62 and 64.

Ashish: No, I don't know him. I had that bike on file. Nice Cafe conversion.

EMS wrote: ↑

Sun Jul 19, 2020 8:30 am

Jerome, I cannot make out the stamping on the motor as the picture is too small and it does not enlarge for me.
If the stampings say 53.3 ?? 55, it means the following:
53 - 1978
3 - March
?? - Day of the month
55 - 55th engine THAT DAY, not over all.
The engine would be worth conserving. I personally know of only 3 documented production motors with lower serial numbers, 61,62 and 64.

Mike, When I enlarge looks like it says 53 2 24 So would that be 53- 1978, 2-Feb, 24 -Day ??
What was the first Month, Day, and if known first Eng # on production motors?
yeah for sure on conserving the motor !

Thanks for info.

Jerome:

It seems like it is indeed a February production. I have dates for an engine which is serial 649 and was made on March 17. As your number is lower, it would have to be a February built if the day date is 24.
The first "production" engine is not known, but the first engine sold to the public is serial number 60. An owner in California has bike VIN number 44 with engine number 61. At one time, a seller in Ohio sold CBX No 45 with engine #64 and someone in Canada, I was told, had bike 43, the second CBX produced for sale to the public, with engine #62
So, there are 59 engines of which we do not know much. Ever so often one of them pops up. Really early ones were prototype "sandcast" motors and were installed in the early 1977 demo and press bikes. How many is not known. And the number when Honda switched from "sandcast" to "diecast" is a mystery. We have to assume, they built quite a few which they ran on dynamometers to test final design and production.

Here are the details of new to me 82. Looks like a difference of 17 between engine number and bike serial number.
Build date of September 81.
Where would I find the frame number?

You show the stamped frame number in the first photo. What else are you looking for?

Dave

The "frame" number is also on the ID plate. It is commonly called the VIN - Vehicle Identification Number.
The difference between frame and engine number is normal and within the usual range.

One thing that "stumps" me is, this is another one of these few occasions where the VIN number and the production date are out of sequence.
I have several bikes on record that have lower numbers and have a 10/81 built date. My "lowest" 10/81 number is 2293.
I have no idea what to make of this

If it's any consolation, researching old BMW serial numbers from the fifties shows the same thing. Lower serial number bikes produced on dates after higher serial number ones.

Dave

My friend at Honda in Marysville offered one explanation:
The VIN-number was assigned/stamped on the frame when the frame was finished/before the paint. The VIN plate was attached when the bike was finally assembled/finished. If a bike was held back for quality issues, the VIN plate could have come much later and actually in the next month.