"Short Wave Sportfishing" wrote in message
...

Here's a couple of suggestions, although these might not be the
answer.

Check the wire along it's route for abrasion, cracked insulation, etc.
You might also want your mechanic to test the coil. Pull the tach and
try it on another engine. I would suspect either the tach itself or a
short somewhere along the wiring route.

I've already eliminated the coil from the equation so it's between the coil
and the throttle. The visible wiring looks good with no cracks. I'll have to
get into the throttle area to examine the connections/wire.

I'm not familiar with the throttle system you use, but I have worked
on a similar age Merc throttle control and I believe the tach wire,
along with temp sensor, oil pressure etc., went to a connector block
and then to the instruments. Pull the connector apart and check for
corrosion, shorts, etc.

I can't remember what my guy called it but the 'switch' inside the throttle
area that stops you from being able to go into gear while the rpm's are too
high may be related. By disconnecting that system at the coil, we run ok,
although after any length of high speed run (25 mph and 3500 rpm), I have to
slow to trolling speed for about a minute before I can get it back into
neutral or manuever into a dock.

Common sense when looking and if necessary, making a drawing of what
you take apart if you take something apart, is a good idea.

Good luck.

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern


Thanks for the reply. We're supposed to get a break in the rain by midweek
so I'll hopefully get to work on it in a day or two.

Ed