I recently read an excellent thread started by rowndman who was getting intermittent artifically high RPM readings and pinging on his Mercruiser 4.3 engine. After much testing, with the help of Don S and others, he finally determined that the shift interrupt switch was the problem.
My 1997 Mercruiser 4.3LXH Gen+ 4bbl is starting to have similar symptons to the ones experienced by rowndman. My questions are pretty basic: Where is the shift interrupt switch? Is it easy to access? What does it do? To disconnect it do I simply uplug it? Assuming that it affects shifting, can I shift from neutral to forward so as to test if the symptoms are still present with the switch disconnected?