I just bought a used temperature gauge for my '78 Mercury Blackmax
(200 HP). The gauge is a Medallion. Do I need a temp. sensor for this
particular gauge or can I simply connect it to my old sensor?

-- John

The gauge is a Medallion. Do I need a temp. sensor for this
particular gauge or can I simply connect it to my old sensor?

You have to be sure the sensor operates in the same resistance range as your
guage. The best way is to get it from Medallion.
"Standard" is a word that outboard manufacturers only have a passing awareness
of. In most cases there is no such thing as standard.