Bentteau 373 engine won't turn over

[Peter M]

My 373 with Yanmar 3ym30 wont start on first turn of the key. Sometimes it takes 7 or 8 times before the engine turns over. Once the engine turns over it starts immediately. Does anyone have a suggestion? I don't think it is the batteries as the starter battery is 1 year old and it eventually starts. I was wondering if it is a contact issue in the ignition key.

Thanks for your help
Peter M

 

[JohnShannon]

when it cranks does it crank normally? I had that issue wouldn't crank alarms wouldn't buzz nothing. cycle the key a couple of times then alarms would buzz and would crank as normal. Loose connection on the engine was the problem replacing the key switch did not help except I have a cool new key.

 

[kloudie1]

LOTS of comments on this Yanmar issue.. bad connections in the wiring harness are almost always the cause.. some folks bypass the connectors with a new larger diameter wire and some folks wire in a relay.. that way the key/pushbutton operates the relay which switches power to the starter relay. Search site for "hard starting Yanmar" and you'll get a bunch of info..
edit: https://forums.sailboatowners.com/index.php?threads/yanmar-53-hp-engine-hard-to-start.155057/

 

[Philip_Oceanis 361]

Valid for Volvo Penta engines, so not sure if it applies for Yanmar.
Check also glow plugs and starter/glow plug fuses (if any).

 

[DougM]

There is a 99 percent chance that the problem is the white wire in the instrument panel harness from the starter pushbutton to the starter solenoid. Bypass that wire, and install a heavier gauge white wire. The direct run with no connecters in between will make the problem disappear.

 

[shemandr]

I can confirm that it is also a Yanmar problem. Do as DougM says, at the very least for the purpose of diagnosis.

 

[reworb]

Sounds like the same problem I had with my 2GM20. The problem was/is the wiring harness, Yanmar cheaped out on the wires from the stater motor they were undersized and non tinned. I replaced the red and white wires (not sure if that's the correct colors for your's) with number 10 tinned wires from the starer motor to the button and key. Never had a problem since, starts first time every time. The non-tinned wires corrode over time and since they are small to begin with resistance builds up not delivering enough juice to the starter. I was told that the multiple attempts to start temporarily lowers the resistance from the heat or something. I read about installing a second relay but that seemed to add a layer of complication and no less work than simply running two new quality wires

 

[Peter M]

Thanks Guy's I will try this out and let you know if it works.

Peter M

 

[Benny17441]

Known malady. Old wiring leading to a voltage drop that fails to energize the starter solenoid. Rewiring, adding a push button switch near the engine compartment or adding an auxiliary relay are the most common fixes.

 

[Bob Mack]

Have a 2007 373 with a Yanmar 3JH4E. Had similar start problems. Traced to the starter switch, disassembled and found that there was excessive lubricant, about the density and color of Petroleum jelly, lubricating the contacts. Thoroughly cleaned and have never had the problem recur.

 

[Guan]

I always advance the neutral fuel level by a third, depress the glowplug switch for 10sec. then the starter but will still six or more turnings before engjne fires.
Is this correct and response normal?

 

[cymeyer]

There is a 99 percent chance that the problem is the white wire in the instrument panel harness from the starter pushbutton to the starter solenoid. Bypass that wire, and install a heavier gauge white wire. The direct run with no connecters in between will make the problem disappear.

Totally agree this is likely the cause.
We have a 2000 MY 3GM30 and had the same problem. Solid wire from starter button to solenoid did the trick.
I would hope Yanmar has since fixed the problem, but who knows.

 

[russconde]

Hi All, When you replaced that white wire with a heavier gauge did you add an inline fuse or wire only? I believe the current white wire has an inline fuse.
Thanks, Russ

 

[Whatfiero1]

A hard starting diesel that when the start button is pushed and engine spins over at full speed just under 1000 rpm on tac is usually caused by fuel loosing its prime or air getting into fuel line and the engine having to crank over till self bleeds itself

 

[LeslieTroyer]

Is the starter spinning but the engine not turning over?? If so could be a sticky bendix or starter motorbearings or battery cables

Les

 

[nfg2u]

Check the wiring to the starter and make sure you have a good ground. Good advice above. Nothing like a little corrosion to keep from having a good connection. Should be an easy fix. My Yanmar did the same thing till I found the culprit, cleaned the wires and made sure I had a good connection. Have not had an issue since.