Topic: Comparing Vin# and Eng# on our SOHC4's

[dhall57]

I like this. By checking there #'s members Johnie and Old Scrambler found out that both there CB750K3's had same build date of 10/72 and that the Eng#'s show that Old Scrambler's K3 came off the line in Japan in October 39 years ago 239 bikes before Johnie's did. And now both have these bikes and both live in Wisconsin. To me that's very interesting to know and gives both a little history on there bikes. So here's my two 750's to compare with your same *year & build date 750's.* Maybe some member out there has another 750 that came off the line right before or right behind mine or his. or something close anyway.

1970 CB750 KO
Vin#10312**
Eng#1031582
build date 4/70

1976 CB750K6
Vin#25479**
Eng#2436837
build date 9/75

[ekpent]

I also have a Baccus 73 that I am anxious to get the numbers off from and compare to theirs.
  Now what I wonder is when they were building these bikes if they would do a very large number of them in one run according to the color. Like lets say for 73 maybe they would do a consecutive run of like 2,000 green then swithch to 3,000 orange,throw in a few brown etc.,and rotate back and forth a little. Seems like that would be the best way if the paint shop was was tooled up and cranking out a certain color.- HHmmm- 

[bryanj]

Nope they just had "sets" of coloured fittings that got fitted and nobody in the factory took note of what colour they left the line in, all Honda can tell you is when a frame number left the line---not even the engine number

[754]

 I siggested those 2 check their numbers.
 On the relay ride, I met a guy with a KO in the 20K range, I went home checked numbers on a motor I had 305 apart!! I am thinking same or next day, when they were made.

 I had suggested a KO registry, might find more close matches or consecutive numbers.

 I have a KO motor and frame, it is about 200 from the end.. last day maybe?

[ekpent]

Seems like they would of had a pre-determined amount of machines in a certain color,maybe depending on which was more popular. Seem to see more Flake Orange 73's left now than the Brown color that year which I hardly ever see,been looking to buy an original in that shade for sometime.

[Don R]

I have a K0, #1014100 without the original engine. Someone mentioned an engine and frame that was very close to mine, seems like within two hundred or so.

[CycleRanger]

I thought about this a while back.

Make list of build date, frame, and engine numbers of all the members bikes and see if anyone has bike that came before, after or was close to theirs.

But I figured too many people would be too paranoid to list their numbers.
Since in the US most bikes are registered by the frame number maybe we can at least get folks to post their engine numbers.

Personally I'm too lazy to go out the shop and get my numbers right now.

[the technological J]

just for the sake of it my last 5 numbers are 42628... my engine and frame match

interesting little tidbit is mine is registered as a 71

[Gordon]

just for the sake of it my last 5 numbers are 42628... my engine and frame match

So the cases were replaced at some point and the engine re-stamped to match the frame number? 

[CycleRanger]

just for the sake of it my last 5 numbers are 42628... my engine and frame match

So the cases were replaced at some point and the engine re-stamped to match the frame number?

That would be my guess as well.  While those numbers do look neater than most restamps, I don't think they're factory.

[736cc]

Those engine numbers pictured are factory, Honda used unique stamps. Matching engine and frame is rare; I saw a matching K0 recently under 10,000 and that was the 1st I've ever seen.
My K0 motor is 43400 something, frame within 110 digits. Built 6/70 and registered as a 1971
Ever notice that frames serial #'s are usually a lower number than the engine? I figure thats because some motors didn't pass muster before installation. Check yours.

[CycleRanger]

Those engine numbers pictured are factory, Honda used unique stamps. Matching engine and frame is rare;

I don't disagree with you that it's possible and those number do sort of look factory, but I'll need a better picture to be convinced personally.

[Axehandle]

Guess I'll be out in the shop looking at numbers this afternoon...  The manufacture date on the frame is 10/72.  Does this mean that the bike is a '72?   Alabama was not a title state before '75 and this thing hasn't been on the road in a long time so there isn't a paper trail to make it anything..   I was thinking I bought it as a '74..

[736cc]

10/72 usually a 1973; September is the traditional beginning of a "new" model year

[KCbarsos]

Seems like they would of had a pre-determined amount of machines in a certain color,maybe depending on which was more popular. Seem to see more Flake Orange 73's left now than the Brown color that year which I hardly ever see,been looking to buy an original in that shade for sometime.

here you go 

[Don R]

I thought the reason the engine numbers are higher was because engines were taken from the line to sell as replacements.

[754]

 I have never seen a replacement engine offered for the 750s.

[bryanj]

They wern't. Story i was told is that the missing numbers are the ones that failed testing, so i theory the only ones with matching numbers for certain would be first one off the line and even then the first engine could have been faulty.

As to the stamped engine number the "B" doesn't look right to me

[mrbreeze]

I can't see a problem with anyone listing their #'s. How could anyone steal your bike in that way?? If someone wants to start a registry.............I can think of no reason not to list mine. Let me know if I'm wrong .