"Buzzihd Beah" wrote in message
...
symptoms:

sits at 160 when batteries are off
jerks down slightly when the ignition key turned on
goes up to ~ 175 when the engine warms up

are they fixable at all?

Probably the gauge. Local boat store may well have one that matches. There
is also a sending unit on the engine that could be the problem as well but I
would try the gauge first.