> What was the years that the changes were made to the 1275cc motors?
Thin wall was 1967 but IMHO that is the best year engine.
I am running 2 of them these days. and still have a goldseal on the shelf.
They have the nitrited crank (EN40B) and a whole bunch of other subtle
goodies. No smog head, centrifical advance dizzy, etc.
I only killed one once back in 1972 when I forgot antifreeze in the
radiator and it was below freezing out.
Temp gauge went down but the engine got hot. Wrist pin came out and
scored the cyl wall. But the crank went into another block.
Toms River, NJ