Yanmar starter solenoid issue

[thomasx]

Hi

I have had some intermittent starting issues with my Yanmar 2GM20, sometimes when I press the start button, nothing happens.
I see some say to connect directly from the start button to the solenoid with a new and lower gauge wire. So I did that. However, the wire that's always been there is the same as always, so changing for a different wire is really just "covering up" for something else. This was more or less confirmed when I noticed that after the swap, parts of the starter button had melted. So, at one time when I had this problem, I measured the current, and when pressing the start button, a very high current was drawn. Hence, the problem was not the connection, in which case the current would be weak, too weak to get the solenoid to act.
Then there are some solutions to add a relay next to the solenoid. That's one way of overcoming the issue with the high current melting the starter button. But the original problem is still there.

So, my belief is that the issue is with the starter solenoid itself, after years of operation it's not working as smoothly as before, and requires more current to act, and sometimes get stuck. A couple of times when the motor didn't start, I tapped the solenoid with a tool, and both times it started perfectly directly after the tapping. So this strengthens my belief in the solenoid issue.

So, now the next step is to remove, disassemble and service the solenoid. Did anyone do this before? Any experience, information etc, to share? Or any links to info on the web. I haven't found anything yet, after some searching.

Thanks, Thomas

 

[LiftyK]

There is a known patch whereby adding another relay solves the degrading wiring issue. I have it in my boat, fitted by a Yanmar agent. If this is the same issue see Starting a Yanmar 1GM

 

[rotrax]

IIRC your Yanmar has a pre-engaged starter, made by one of the large Japanese companies. The solenoid throws in the drive gear first - hence pre-engaged - and completes the heavy current circuit to turn the engine via the starter motor once the gear is fully engaged.

A big improvement on the inertia starters of an earlier period.

You must remove the starter motor complete to attend to the solenoid, which is integral, it will be the smaller piece screwed to the main body.

Unless you find dirty or poor connections or the engaging lever stuck on its pivot you are unlikely to be able to repair it yourself.

If the solenoid has a defective winding it must be replaced.

It will, however, be a good exercise to remove and inspect it as well as subsequently being able to identify it from its stamped in numbers.

Many independent auto electrical specialists can repair or replace these starters. When you have removed it and can decide the best way forward you can proceed with a fix.

Good Luck.

 

[snibble]

You say the solenoid takes a very high current. How high? I rebuild quite a lot of these starters and the solenoids rarely fail. It's not unusual for the solenoid to take around 35A to engage the starter and the relay byepass isn't a bodge it's redesigning around a known weakness. Alternatively the tapping of the solenoid curing it is indicative of a problem with worn or sticking motor brushes which will usually manifest as an intermittent failure. Don't remove the solenoid with the rest of the motor intact, the hairpin return spring locates the engagement fork and is fiddly to re-engage. I'm not certain exactly which starter you have but it will have either a plastic clip on cap or a cover held with two screws on the back assuming it's one of the usual hitachi machines. If you can post a picture of the starter I can advise further.

 

[rotrax]

No, I said the solenoid COMPLETES the heavy current to turn the engine. 35 A is very likely the level of current drawn by the solenoid while it is doing this.

I have not been 'on the tools' professionally for 15 years, but fix as much of my own - and friends - stuff as I can.

I was once responsible for the repair shop for Lucas Service at Park Royal in West London, employing over 15 technicians/mechanics.

We handled ALL lucas group products, including CAV, which I see you have posted on elsewhere.

Well done, good stuff.

 

[Mikedefieslife]

Does the starter spin up at all A) when connected to the solenoid b) when jumped?

If the starter is spinning but no engaging this is mostly a solenoid problem. Had the same issue (nothing to do with the wiring).

If on the other hand, you push the button and bugger all happens, or it only happens intermediately, this could be a) solenoid problem, and/or a wiring issue.

I bought a brand new hitatchi starter in Greece, and by Italy the solenoid had already failed. I resorted to starting the engine by directly connecting the starter to a big 1 2 off switch. When I got back to Spain I bought a Chinese solenoid for about £40 and installed that. It's been fine for last 4,000nm.

 

[Talulah]

Because 'parts of the starter button were melted' I suspect the main cable between the battery and the starter motor has become disconnected. The starter is then trying to draw the current from the thin power cable.

 

[olam]

I changed the wire on mine for a heavy gauge and never had another problem.Very easy to do.
Also added a piggy back wire from the solenoid to another start button in engine bay which can bypass the
ignition switch completely.

 

[RichardS]

Because 'parts of the starter button were melted' I suspect the main cable between the battery and the starter motor has become disconnected. The starter is then trying to draw the current from the thin power cable.

From memory, isn't the activating +ve connection from the ignition switch to the solenoid normally isolated from the heavy duty +ve from battery to starter motor?

Richard

 

[Talulah]

From memory, isn't the activating +ve connection from the ignition switch to the solenoid normally isolated from the heavy duty +ve from battery to starter motor?

Richard

Normally but you see so many hacks over time that nothing surprises me.

 

[VicS]

Post deelted

 

[RichardS]

If they were connected the solenoid would be energised all the time.

Indeed .... although I'm surprised that you're quoting me rather than post #10.

Richard

 

[snibble]

From memory, isn't the activating +ve connection from the ignition switch to the solenoid normally isolated from the heavy duty +ve from battery to starter motor?

Richard

The solenoid terminal connects to two windings, one of which is a very low resistance finding it's -ve through the motor itself. If for whatever reason the contacts fail to close or the main supply is missing the current taken can be very much higher than the switches are continuously rated for.

 

[VicS]

Hi

I have had some intermittent starting issues with my Yanmar 2GM20, sometimes when I press the start button, nothing happens.
I see some say to connect directly from the start button to the solenoid with a new and lower gauge wire. So I did that. However, the wire that's always been there is the same as always, so changing for a different wire is really just "covering up" for something else. This was more or less confirmed when I noticed that after the swap, parts of the starter button had melted. So, at one time when I had this problem, I measured the current, and when pressing the start button, a very high current was drawn. Hence, the problem was not the connection, in which case the current would be weak, too weak to get the solenoid to act.
Then there are some solutions to add a relay next to the solenoid. That's one way of overcoming the issue with the high current melting the starter button. But the original problem is still there.

So, my belief is that the issue is with the starter solenoid itself, after years of operation it's not working as smoothly as before, and requires more current to act, and sometimes get stuck. A couple of times when the motor didn't start, I tapped the solenoid with a tool, and both times it started perfectly directly after the tapping. So this strengthens my belief in the solenoid issue.

So, now the next step is to remove, disassemble and service the solenoid. Did anyone do this before? Any experience, information etc, to share? Or any links to info on the web. I haven't found anything yet, after some searching.

Thanks, Thomas

Rather than tapping the solenoid try turning the engine by hand a little. If it's sticking or jamming you may hear it all spring back into position.
(i'm having the same problem with the car at the moment but have not yet been able to get the starter motor off or investigation. Easy job when I was younger I guess but now will need assistance so will have to wait until/ if we ever get back to normal life)

The service manual contains a lengthy section on the starter motor including diagnosis, dismantling, repair, reassembly and testing.

You can down load the manual from Barrus's website

Manual Downloads | Barrus

The manual for 1GM10 covers the 2GM20 ( and others)....

 

[Spyro]

You mention it’s the same wire that’s always been there but there are several connections and loom plugs in between. They become high resistance joints over time. Replacing it with one continuous wire from push button to solenoid usually cures it. Have you connected your new wire to the starter and not the solenoid by any chance?

 

[lw395]

The solenoid terminal connects to two windings, one of which is a very low resistance finding it's -ve through the motor itself. If for whatever reason the contacts fail to close or the main supply is missing the current taken can be very much higher than the switches are continuously rated for.

That is the key.
Pre-engage starters are often more complex and subtle than people realise.

A dodgy starter can destroy switches or 35A relays in no time.
And some of these faults feed on each other. Dodgy main contacts abuse the relay which makes it chatter, causing more wear on the main contacts.
My first vehicle with a PE starter was a MotoGuzzi. A new start was a week's wages which I couldn't afford. I learned a lot from that bike.
You can usually start a Guzzi by shorting the big terminals together. Guzzi riders generally had 50p pieces with bits burned out of the edges!

 

[snibble]

That is the key.
Pre-engage starters are often more complex and subtle than people realise.

That's very true. I was once sitting in the reception office doing some paperwork when a bloke put a Lucas starter on the counter and asked for a new solenoid to be fitted. I hopped up and told him he most likely just needed brushes. He just threw his eyes skywards and said "look, just fit a new solenoid will you". So I did. He brought it back because it didn't work. Called the boss and in front of the customer I explained to the boss that the problem was a bad diagnosis and the gentleman should refer back to the untrained and incompetent person who made that diagnosis. Produced job card with customers instructions on, confirmed by receptionist. Grinned at customer and told him he just needed brushes. Later that morning got a phone call from a nearby firm who I had a good relationship with and he had taken it there complaining that we had fitted a solenoid when all that was needed was brushes! The customer is always right even if sometimes he's a dick.

 

[Gatewaysailing]

i got 2gm20 starter i stripped it totally and solenoid fine and engages but the main motor itself wouldn't turn even after releasing and cleaning the wires and the brushes so am confused as to what to do next

 

[PaulRainbow]

Take it to your local auto electrician.

 

[Gatewaysailing]

Take it to your local auto electrician.

that will cost more than replacing the starter motor