Re: Much difference between 92 and 97 Force Motor
The engine block is almost 100 % the same. between 1990 and the last year produced ('98?,'99?), Mercury phased out Force parts. They changed lower and midleg units and water pumps, replacing them with Mercury designed ones, changed the fuel pump to a Mercury designed one, changed reeds, changed control cable mounting and function, and changed ignition to Mercury designed ignition.
Some changes appeared to be positive while others I will reserve judgement on.
The engine was discontinued because Mercury already had a low priced engine line--Mariner-- and coming anti pollution laws made it too expensive to redesign the 50 year old Force block design to comply.
Older Chrysler and Force engines seem to have a loyal following of people who are willing to work on them and keep them running. But, there is no doubt in my mind that sold as a new engine they would just not have been competitive in the market. Apparently Mercury thought so too.