Is Yanmar starter a non-starter

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Homer J

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I have a Yanmar 3GM30 which works well and starts very well when the starter motor turns

The problem is that I may have to push the starter button 4 times in order to get the starter to crank - this doesnt matter whether the engine is hot or cold.

I know it isn't the battery as these are all new. I was thinking it was a problem with the starter button and was going to replace it but.......

1) In the box of spare parts that came with the boat is another starter button (I'm not sure if old or new) so I suspect it has had this issue before (I know I could swap it over and see, and may do this) and
2) I saw on an old thread that people have had starting issues from a poor earth or solenoid

So my question is - is this a known Yanmar issue and is the starter button the place to start?

I reckon I could replace the started button but beyond that my mechanical abilities are poor

Any advice would be great
 
Surely easiest route is to remove, clean and reattach both the +ve and negative at the starter motor end AND the solenoid as well as replace the switch (with a known new one). And perhaps remove, clean and reattach connections at the battery end too if you've any reason to suspect them. Those jobs should be straightforward and unlikely to take very long.

If you've then still got an issue, the solenoid would be the next thing to suspect. If, after that, you've still got issues, take off the starter motor and get an automotive specialist to service it, which should cost around £100.
 
It's a perennial problem with this engine's wiring. There are at least four connectors in the wire between the starter switch and the solenoid connection. Cleaning them up will help but the best way is to run a single wire instead. I did this about 5 years ago and it has never failed since. From memory it is the white wire at the switch but check first.
 
vyv_cox said:
It's a perennial problem with this engine's wiring. There are at least four connectors in the wire between the starter switch and the solenoid connection. Cleaning them up will help but the best way is to run a single wire instead. I did this about 5 years ago and it has never failed since. From memory it is the white wire at the switch but check first.
Click to expand...

So you think it is unlikely to be a problem with the switch?
 
There is a "known" problem with Yanmar starters which is caused by a faulty relay. This relay is a smallish black plastic item which is located on the rear of the engine; it has about four small wires going to it. These are a known problem on charter boats ( as explained to me by a charter company mechanic) where the relay fails "on" and burns out the starter motor which does not disengage.
On my boat I had a problem where intermittently the starter motor would fail to turn and I needed to try four or five times, and then it would turn and the engine start. I obtained a spare relay from said mechanic (cost about 35 euros IIRC) and when I came to replace the original, one of the wires fell off!!! As I now had a spare relay, I replaced it anyway; this was about six or so years ago, and since then it has been perfect.
This relay is not the large one mounted on the starter motor but a small black plastic item mounted on the rear of the engine quite high up.
Alan.
 

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Thanks Alan - I will look into this on Saturday when I am at the boat - thanks for the advice and the photo which enables a ham fister like me to know what to look at :)
 
As far as I know there is no relay on the GM series but as Vyv says it is a known problem usually cause by a high resistance joint. I fixed the problem on mine by cleaning, redoing all connections between the push start button and the starter solenoid. I reckon the large white plugs on the wiring loom were the problem.
If you google GM series starter problem you will find you are not alone.
 
alan said:
There is a "known" problem with Yanmar starters which is caused by a faulty relay. This relay is a smallish black plastic item which is located on the rear of the engine; it has about four small wires going to it. These are a known problem on charter boats ( as explained to me by a charter company mechanic) where the relay fails "on" and burns out the starter motor which does not disengage.
On my boat I had a problem where intermittently the starter motor would fail to turn and I needed to try four or five times, and then it would turn and the engine start. I obtained a spare relay from said mechanic (cost about 35 euros IIRC) and when I came to replace the original, one of the wires fell off!!! As I now had a spare relay, I replaced it anyway; this was about six or so years ago, and since then it has been perfect.
This relay is not the large one mounted on the starter motor but a small black plastic item mounted on the rear of the engine quite high up.
Alan.
Click to expand...

I've often wondered what that relay was for on my 3YM30s, although I'm not sure that the GM series is the same.

Richard
 
You can eliminate button and low current wiring connections by jumping the starter solenoid spade terminal and the large power in terminal with a screwdriver shaft. (watch your dangly bits...)
Next step would be getting a helper to hold the key/button in the start posn and tapping fairly gently with a hammer (the starter, not the helper)
 
Apologies to OP, I read 3YM instead of 3GM!!
I think my comments and drawing are only applicable to 3YM series.
Sorry for causing any confusion.

Alan.
 
If you get stuck and it won't go at all you can use a jumper wire direct from the +ve on the battery to the starter Solenoid. A hefty ready made one with a croc clip on one end is handy to have.
 
Spyro said:
As far as I know there is no relay on the GM series but as Vyv says it is a known problem usually cause by a high resistance joint. I fixed the problem on mine by cleaning, redoing all connections between the push start button and the starter solenoid. I reckon the large white plugs on the wiring loom were the problem.
If you google GM series starter problem you will find you are not alone.
Click to expand...

When we had a 3GM30, the starting switch on the instrument panel was found to have dirty contacts. It's pretty simple to dismantle. Wire wool or fine sandpaper will remove the corrosion. Silicone grease added among the contacts will keep it clean for a long time after re-assembling it. Unlike car starter switches- these are very simple!
 
alan said:
There is a "known" problem with Yanmar starters which is caused by a faulty relay. This relay is a smallish black plastic item which is located on the rear of the engine; it has about four small wires going to it. These are a known problem on charter boats ( as explained to me by a charter company mechanic) where the relay fails "on" and burns out the starter motor which does not disengage.
On my boat I had a problem where intermittently the starter motor would fail to turn and I needed to try four or five times, and then it would turn and the engine start. I obtained a spare relay from said mechanic (cost about 35 euros IIRC) and when I came to replace the original, one of the wires fell off!!! As I now had a spare relay, I replaced it anyway; this was about six or so years ago, and since then it has been perfect.
This relay is not the large one mounted on the starter motor but a small black plastic item mounted on the rear of the engine quite high up.
Alan.
Click to expand...

If you don't find a relay where shown look carefully at the wiring going to the starter solenoid. On my boat with a bigger Yanmar I found a standard automotive relay similar to this one just hanging on its wires to one side of the engine. https://www.ebay.co.uk/itm/NEW-12-2...hash=item4b5729d1b5:m:mDrq_UPX7OEo9fLUfx0KLpg It was used to energise the solenoid and had become unreliable. Replacing it solved the starting issue, and I now carry a spare.
 
Norman_E said:
If you don't find a relay where shown look carefully at the wiring going to the starter solenoid. On my boat with a bigger Yanmar I found a standard automotive relay similar to this one just hanging on its wires to one side of the engine. https://www.ebay.co.uk/itm/NEW-12-2...hash=item4b5729d1b5:m:mDrq_UPX7OEo9fLUfx0KLpg It was used to energise the solenoid and had become unreliable. Replacing it solved the starting issue, and I now carry a spare.
Click to expand...

I use a very similar one on the windlass fitted to my motorsailer. Helps to cut down arcing in the switch. I don't think they come as standard with the 3GM30.
 
With the 3GM it isn't necessarily as simple as replacing the thin wires carrying 40a current to the solenoid. Though adding a relay does help.

I found that my starter died, so I bought a complete new unit.

I replaced all wires to the starter/solenoid unit, and bypassed the loom with with 6mm2 wire, added a relay, and a better fuse block. After that I still had a problem where the relay would engage but the starter wouldn't start.

Eventually it just completely failed again. So I bypassed everything, and ran the starter directly from the battery via an ignition protected switch suitable for a 400a load. This worked, so shows that the new starter was good, but the solenoid (which was new as part of the Hitachi starter unit) had died within just a few months.

I have now ordered a brand new solenoid, fitted it, and while the stater will spin up instantly and very strongly on the push of the button, but it doesn't make contact with the engine until the 2nd or third press. I have noticed that the solenoid is supposed to throw out some kind of lever to help the starter engage the engine. Presumably it's not doing that reliably.

Anyway, I'm just posting to show that there can be a variety of different starting issues regarding this engine, over and above the poor wiring loom.
 
tjbrace said:
We have a 3GM30 and have a similar problem. I just ‘hunt around’ the depressed button until it makes contact. So far so good.
Click to expand...

I am doing the same thing but doesn’t it concern you that it is “so far so good”? What happens when it isn’t Sod’s law says it won’t be on the mooring but when you really need it.
 
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