internet. 5.30 am and I was up, and on my PUSH bike pounding the tarmac. Some of you still had a hold of it!
Interesting discussion on the engine #s and VINs. The thing with the casting dates on the cases is that this is, (if these numbers are the actual casting dates), the date the case was cast at the foundary. This is not necessarily the date the cases were machined or the date the motor was assembled. Mind you the probability is that machining and assembly followed not long after casting. The cases, also prior to machining, were not necessarily a matched pair. It was only during machining that a set of cases became a matched pair. Again, one can assume that the cases were laid out in the machine shop in pairs. The magic day however was when that fellow with the hammer and numbered stamps did his/her thing. Probably not a lot of time passed from casting to number crunching, nevertheless a lot of assumptions. One thing though is that Honda had a habit of numbering prototype engines as part of the production run, thus the first few engines were probably prototypes/come test engines. Methinks possibly engine # 4, 5 or 6 was the first actual running CB750 engine in a frame.
VINs on frames is another matter entirely. The number was the last thing done to a bare frame. From my understanding, the paint went on before the number, so the best we can hope for is that a week or so would be the time from manufacture to the numbers being stamped on the frame. Steve raises an interesting point in relation to the 69 date. The point that would need to be asked if we accept some of the assumptions, is what if the frame was made, in say, late August and wasn't stamped until September. Does it get an 8 or a 9. But then how did the frame makers know when to stop placing the horn tag on the RH side rather than the LH side. Possibly this wasn't so much determined by a frame number but a point in time, ie: "as from Monday we will no longer make any LH horn brackets". In the end, I wasn't there but I am certainly interested in the answers. Come on you guys with the knowledge, add to these discussions. This should not be secret squirrell business KP
