Yanmar GM series - intermittent fail to crank

[searomer]

This document offers an inexpensive fix for Yanmar GM Series engines that do not always crank every time the starter button is pressed. This document does not deal with engines that always crank, but do not always start.

See the two page attachmet.

[Inlet Marine Services]

The gm series loses power through the harness over time. The easy way is to install a relay. I have a wiring diagram just e-mail me. inletmarineservices@comcast.net

[cal40john]

Originally Posted by Inlet Marine Services

The gm series loses power through the harness over time. The easy way is to install a relay. I have a wiring diagram just e-mail me. inletmarineservices@comcast.net

So are you disagreeing with the OP's diagram of adding a relay?

John

[senormechanico]

My previous boat had a Yanmar 3hm35f and had that problem.

I traced it to a weak connection in the wiring connector at the aft end of the engine.

The multi connector plug has brass connectors which are split pins. The pin which

powers the starter solenoid needed to be spread apart and cleaned.

That fixed it for several years, and was still working when I sold the boat.


Steve B.

[hugosalt]

Had exact problem on my 3gm, did not crank every time button was pushed,
would always start but would have to press button several times before it caught. Was not happy! Added inexpensive relay 2-3 years ago. Now starts first time every time....I concur...used to lose voltage through harness/wiring as
they aged.

[westsail42]

Im confused, are you talking about "cranking" or "catching"??

My 3GM seems to crank just fine, but it catches like crap when it is really cold. In the winter I need to put a space heater on the block the day before to improve chances of detonation in the first crank.

This engine coulda used glow plugs.

[hugosalt]

Talking about not cranking everytime button is pressed...catching in cold weather is yet another adventure. Not that much of a problem for me since I
started the following...raising the rpm's 200-300 before starting and flippping
off 1 or 2 of the decompression levers. As soon as the motor catches I reduce the
throtle and flip the levers back to compression. Use this in temps of around 30
to 40-45f. with a stong battery. Don't know if Yanmar would recommend, but
works for me.