OK, I am a new boat owner and am learning the hard way. I am pretty
sure that I have fried the water impeller in the stern drive. I have
an '81 Glastron SX-190 with a Mercruiser 228hp 305. I didn't know,
until now, that the boat should never be started even for a few
seconds without water supply at the stern drive. Well sure enough, I
got the boat out to the lake for the first time this year and I have
an overheating problem. I took out the thermostat at the lake
thinking that maybe it was the culprit. Still the boat overheats at
idle. When I rev the engine to about 2000 rpm, it cools back down.
The only thing I can think is that the impeller is not working at idle
speed and barely working enough when I get it up to 2000 rpm. Does
this sound like the impeller is working poorly or could it be that I
need to put in a new working thermostat? The stat that I took out was
140 degrees. Is this too cool or the right one for this engine? Any
info would be appreciated. I am good with cars but am learning
quickly that not everything I know is true anymore (i.e. cranking the
engine and running it without coolant for 5 seconds is NOT acceptable
like it would be with a car). Any other things I should be aware of
would be appreciated. Also, there appears to be quite a bit of
voltage loss in the 23 year old wiring. I am thinking about rewiring
the boat. Any advise or horror stories?

Chris