Re: Temperature gauge on Force 50?
Teleflex makes two style temp gauges (probably others do too). One has the sender pressed against the head by a bracket that is held in place by a head bolt. The other is the more traditional sender that screws into an opening in the block. On my 1985 Force 85 hp, there was a metal plug in a hole on the top of the block that was removed and a fitting installed to put on a tell tale. That same location can have a temp sender installed.
So, check for a plug that you can remove (either slot for screwdriver or hex wrench) so you can decide which style you need. Also check the tell tale thread at the top of the forum for lots of pictures of people who used that port. Should help you decide.
Mark