Mercury 3 and 4 cyl 75-125 motors. parts interchangeability?

[derekfl]

looking at a few 75-125 3 and 4 cyl non-force motors. late 80's thru mid-00's. and i see a 50 lb weight diff between early ones and the rest. wondering where the weight diff comes from. and what fits what if i get a couple. primarily whole powerhead, trim assy and lowers. are they all the same gear ratio? thanks.

[InjectorService]

From what I see there is a lot of interchangeable parts. Pretty reliable little motors. Easy to work on. Later motors had a CDM ignition system. There were 3 ram trims and single, maybe that's the weight difference? Lower units are all interchangeable although the guts changed a lot. 3 jaw dog, 6 jaw dog, number of teeth etc.

[woody]

I think the pistons from a 2.5 v6 are also interchangeable with those outboards .

[derekfl]

i would assume either port of starboard, not both...