Engine not starting

[Michael Ellis]

This 1995 Robinhood 36 is a new boat to me and so there will be many "firsts". This "first" I hope is a "one off". We had motored out of the marina and sailed for about an hour. When I turned the ignition key to restart the engine I heard the alarm but there was no response from the engine. After doing this about six times, the engine did respond and restarted. However, until the engine did finally restart I was nervously weighing my options. The engine is a Yanmar 3JH2E. Does anyone have a suggestion?

[Keith]

Not a lot of information to go on but I'd check battery, starter and ground connections. Clean them up and ensure that they are tight.

Keith

[Frenchy]

Yes, not much to go on. One little bit of diagnosis you can do is note if the voltage drops when you turn the key.
You probably have a voltmeter on the engine panel. If it doesn't drop, there is a bad connection somewhere between
the key and starter or the starter pinion is not engaging. Sometimes you can hit the starter motor with a hammer
to dislodge the stuck pinion (while keeping the key turned) and that will allow the engine to start.
If the voltage drops, you may have a weak battery, bad starter motor or the engine may be hard to turn
over for some reason.
It would be a good idea to solve this problem before you go out again. - Jean

[gonesail]

i was going to suggest replacing the starter button but am thinking this yanmar doesn't have one of those. next thing up is to check the contacts of the ignition switch. good luck. nice boat.

[Jim Evans]

I agree that there isn't much to go on, but your symptoms sound identical to what I went through with my Yanmar 3GM30F on my CD33 back in 2009-10. I went through the wiring, cleaned all the connections, and still, the starter button engaged the starter only intermittently. And then I installed a starter relay - one of these: https://www.amazon.com/gp/product/B001C ... UTF8&psc=1 - and I've never had another problem with starting the engine since 2010. It's an easy install, and worth a try.

[Michael Ellis]

Jim,
Easy is a relative term. On the 36 the Yanmar 3JH2E doesn't have much clearance on the starter motor side. I think the only access would be from aft of the engine. I might be too old and too big to make that journey. However, thanks for the recommendation on the starter relay.

As I sit at the kitchen table trying to figure out the situation, I put the fact that the engine always has started on the first try when the electronics have not been turned on yet. It has just been after we have sailed with the electronics turned on that the engine has been hesitant to start. It might be the situation is marginal enough with the electronics turned on there isn't enough power to actuate the starter solenoid, but with the electronics turned off there is. Not a solution, but in the moment of crisis it might be good to know. When next on the boat I will check this out. I will also see if I can find someone small enough to access the starter motor.

Mike

[Michael Ellis]

Jim,
With regard to the starter relay, I am guessing at the function. I assume the issue is there is insufficient current via the existing wiring to actuate the starter solenoid, but by using the ignition switch to actuate the starter relay which when closed provides a direct path from power source to starter solenoid you effectively have bypassed the old degraded wiring. Do I have that properly understood?

Mike

[Jim Evans]

Hi Mike - as far as I understand it, I think you have it correct. Somehow, the relay provides additional current to the starter. I learned of the tip about using a starter relay, and this one in particular, from a very old post on this forum - and it solved my problem.

[mgphl52]

It is very possible that your starter solenoid is sticking or worn too much to work properly. This happened on an ex-wife's car years ago and I pulled the solenoid, cleaned it and all worked fine... for a bit. After doing that twice, I just replaced the solenoid!
BTW: as I understand it, the solenoid actually is a relay switch...

[Bill Goldsmith]

I second the suggestion to check all connections. Wonky connections can cause this kind of intermittent failure. Happened to me 10 years ago and found a loose-ish ground-to-engine wire. I removed the connection, cleaned it up and reinstalled and it's been fine ever since. The ignition/alarm circuit is separate from the starting circuit.

[Kailua Kid]

Looks like you have gotten some very good advice on this already. I would add only that it is highly likely the issue is an intermittently bad connection in the starting circuit. Two ways to go at that: Clean and re-tighten each connection in that circuit, or use a multimeter and check voltage at each connection while someone turns the key. Likely, the culprit connection(s) will show lower than 12.5 volts. If the connections are proved up good, then it is most likely the starter motor or starting solenoid at fault. As mentioned above, sometimes a few taps with a hard object against the case of the starter and or solenoid can coax the starter to work; if so, you will know to pull the starter and take it in for testing and repair or replacement.