Snapping drive chain.

[Silja]

In 1970 I was trevelling with some friends from Sweden to the Isle of Man. In the group was a new CB750 delivered in the autumn 1969 in Sweden. At our way back to Sweden the drive chain snapped in a bump a made a hole in the engine block.  The chain was obviousily too tensed. On that model there was no protection for snapping chains in front of the small sprocket on the outgoing shaft from the gearbox. Later there were a cover to protect the engine block from such disasters. Was the CB750 in our group one of the very first models, please? The hole was later repaired with some stuff called Belzona!

[Sam]

Hi Silja!

It was, most likely, an early diecast (7,415 and up engine number). The sandcasts appear to have ended sometime in September of 1969. To my knowledge, only a few sandcasts were ever shipped to Europe (the elusive French sandcasts). Perhaps some of our European members can chime in!

Welcome to the forum!

[kettle738]

The old style parts books are very useful in that they show the first serial number supplied for each market..... so, Germany got some sandcasts from serial number 1005084 and France from serial number 1003495; it doesn't say how many of course and the Netherlands had to wait for diecast number 1031084.   Smaller markets presumably drew their supplies from whichever neighbouring country Honda nominated. 

The UK never received sandcasts, (bar the pre production Brighton bike) the first serial number for the UK was 1010369 which as it happens belongs to me.  Depending on where Sweden drew their stock from......if it was France or Germany then it's possible, but if it was the Netherlands, not so according to Honda's own publication...... unless anyone knows different of course.

Mick. 

[Silja]

Is it possible to see in those part lists when the cover in front of the primary sprocket was introduced? The chain piled up in front of the sprocket and made a hole in the crank case.

[Nielsen]

It is not in the parts list from 1st April 1969, but in parts list from December 20. 1971 the protector is introduced from CB750E-1026144. I thought it was made for sandcasts, but it seems not to be the case.

[Silja]

OK Nielsen. Things sorted out. Thank you!