While the construction of the 1200 engine was different to the A12 that was used in the 120Y [the B210 version from 1974 to 1977] the specs were pretty much the same. Same cam timing, compression ratio, even the head casting was the same in the earlier A12 versions.

The carburettor was a different sub model of the same Hitachi that was used on the 1200 & yours might have an electric choke and/or an idle cutout solenoid, but it's still the same basic carb.

Power output will be the same, or so close it doesn't matter, so once behind the wheel you won't be able to tell the difference.

Thanks

It's not the A12A with the swirl port head so no loss of performance there thankfully, also we didn't have to have carbon cannisters over here until 1980 or just before, not sure about Portugal though. There may have been slight revisions to the Hitachi carby between the 1200 motor and the A12 motor. I'm sure DD's listed them in that tech section article

I got an early A12 in my 120y! Is there any performance diferences between the one i got and the late A12?