I have a strange problem that has cropped up. I've owned this boat for several years so I am very familiar with the engine
and systems. I went for an overnight cruise
the other day, tied up at the end of the day, and hooked up to a shoreside power provide by a town on the water
. Tachometer was working normally at this point.
The next morning, I started the boat and the tachometer is reading high - I mean really high, by about 900-1000 rpm
. You could tell by the sound, but as I said I know this boat and the rpm
it takes to make my cruising speed of 7 knots under power, and it was reading about 1000 rpm high.
The tach drops to zero when the engine
is off, and I have not worked on anything or fiddled with the alternator
to cause this. Nothing is slipping and the RPM is really not as high as it is reading - I've verified this with a phototach.
Anyone got any ideas as to what could cause this, and more importantly, what could fix it? The boat is a 1979 Gulfstar
37 - engine a 1991 replacement, no problems prior to this, as far as I can tell the gauges are the orginal that came with the boat....
I've checked the forum archives
, and don't seem to see anyone that has had this problem....
Old boats, what we buy when we think we have too much time on our hands......