72 and 73-750's all used the same "combat breather" cases until the end of production. The early cases had the machining for starters done, but as later 20M3S the hole was blocked off and unused.
L.A.B. said:The hole (with cover plate) was intended for an electric starter motor, not to blank off the 20M3 "distributor" (points housing) hole, as the case went from points housing (20M3) to 'solid' for the early 20M3S models.
The hole intended for the starter motor (with the cover plate as the electric starter was never fitted) is supposed to have been introduced at either 136618 or 133618 depending on the source of the information, so around mid-70, this continued until around mid-72 when it became a 'solid' are again.
Danno said:Seems like it would have been much simpler than all the monkey-motion of the Mk III setup. It would be interesting to see what sort of starter drives/clutches they had planned.
Madnorton said:One of the starters have recently surfaced, sadly the source is unknown, but the person had bought one and inquired why it would not fit a MK3! having assumed it being advertised as Norton Electric start motor would fit.
READS; LUCAS TVS. 26925012A M3. TYPE NO; 26515A 12V. MADE IN INDIA, MAY 1972.
FAR SPARES HAD ONE OF THESE LISTED FOR A NORTON 750 COMMANDO 1971 - 1972 ENGINE BUT YOU MUST BE YOUR OWN EXPERT!!
L.A.B. said:It appears the original (Lucas then, not Prestolite) starter motor was a total failure, apparently, it had no anti-backfire device incorporated into the drive, the experimental starters would regularly self-destruct when the engine backfired so never did go into production!
worntorn said:This raises a question about the current Pre MK3 starter systems from Alton and CNW. Do these systems have some sort of anti-backfire device incorporated in the design?