Here’s a diesel question for Marty Chin or anyone who’s experienced & solved
this particular Yamaha 3GM30F problem.
90% of the time, I press the button, solenoid clicks in, starter turns
over, engine starts.
Last summer, after a nice sail north from Solomon’s on the first leg of
our cruise to Maine I turned the key, hit the button, heard a faint click,
nothing more, no start. This was after many months of no-problem starts,
nary a problem with it. So we tucked into the Rhode River, anchored for the
night and started investigating.
Figuring that it might be a solenoid problem I shorted across the battery
cable lugs on the starter and sure enough it turned right over and started.
Let it run for a while to charge the batteries, turned it off, let it cool
down a bit and then tried to start it again. Push button, click, but no
The starter switch connections on the solenoid looked a bit oxidized so I
cleaned & retightened them, hit the starter button and she started right up.
Problem fixed? No.
On the trip to Maine & back she usually started normally, but on a
totally capricious schedule it had the same problem about one out of every
ten starts or so. I can always get her running by shorting across the
solenoid lugs, and after that she usually starts normally for at least a few
times, then reverts to the same problem.
If this was one of the “old load” $100 cars I used to drive many years
ago I would just replace the solenoid. Cheap, easy, and if it turned out to
be something else, not much time or money down the drain. But the 3GM30’s
starter & solenoid seem to be an integrated unit, not friendly to
disassembly and repair. I’m not sure what’s inside that Yamaha solenoid,
but some of the old automotive ones had a copper disc inside that rotated a
little bit everytime the Bendix engaged and thus presented a different and
theoretically less-oxidized and pitted surface to the internal contact
points. If a stout whack on the outside didn’t jar it enough to make a
fresh contact, they were easy enough to take apart and clean. Or replace.
On the way back to the Chesapeake we stopped for fuel in Mamaroneck and the
diesel mechanic at the original Post Road Brewer Yard said something to the
effect of “Oh, a lot of those Yanmars have that problem, probably not a
tired solenoid, you just need a heavier gauge of wire from the starter
switch to the solenoid, that’ll fix it.”
So. Solenoid? Starter switch? Wire gauge? Gremlins?
What’s the most likely problem/solution to address before I just start
disconnecting inaccessible wires to check resistances, or replace the switch
& starter/solenoid assemblies. Anyone had this intermittent problem?
(Itchen, BCC 73)