Yanmar gm10 won't start

[steve yates]

My mates can't get his engine to start, it's an old gm10, with the pull rod and no glow plug.you turn the key then press a button and it starts, normally. Nowt happens when he presses the button tho.
Battery has 12.7v,
It has two decompression levers on top.
What should he look for first, I've suggested following the wiring to the ignition and making sure it's intact.
Can he do anything with the decompression levers?
Any other ideas?
I think these can be hand started, am I right? If so what's the procedure with the decompression levers?

 

[Judders]

First off, check the kill switch (I looked very silly the other week!).

Is the starter motor not turning at all?

I tend to find that if I flick the decompression up and turn the engine a by hand a few times it'll then get going eventually.

 

[RichardS]

My mates can't get his engine to start, it's an old gm10, with the pull rod and no glow plug.you turn the key then press a button and it starts, normally. Nowt happens when he presses the button tho.
Battery has 12.7v,
It has two decompression levers on top.
What should he look for first, I've suggested following the wiring to the ignition and making sure it's intact.
Can he do anything with the decompression levers?
Any other ideas?
I think these can be hand started, am I right? If so what's the procedure with the decompression levers?

If, as it appears, there is no clicking from any solenoids or relays then it's definitely an electrical problem .... probably a broken or corroded connection.

It should still start on the handle. Open the decompressors to relieve the compression and spin the engine over using the handle. Try and get it up to a reasonable speed then drop the compressors whilst still turning the handle and she should start.

Richard

 

[Don107]

There is a lot of information on the net about this with the 1 and 2 gm series engines

http://www.ybw.com/forums/showthread.php?461325-1GM10-Starting&highlight=2gm+not+starting

Mine did it a while ago and based on information on the net i unplugged the engine wire harness from the control panel and plugged it back in and in the wiring harness to the engine there is an inline fuse holder which i removed the fuse from, cleaned the fuse holder and refitted the fuse

Not sure which one fixed the problem as i did the both at the same time but it fixed the problem

Regards Don

 

[steve yates]

It started after 15 mins of him buggering about, he's not sure what he did, which is a shame as he can't replicate it next time

If you dont press the button at bottom of gear lever to disengage the clutch, would it still start? Just wondering if he had forgotten to do that. Otherwise he wiggled wires and opened the compression levers.

As there is no glow plug on these, are they prone to not starting if cold?

 

[VicS]

My mates can't get his engine to start, it's an old gm10, with the pull rod and no glow plug.you turn the key then press a button and it starts, normally. Nowt happens when he presses the button tho.
Battery has 12.7v,
It has two decompression levers on top.
What should he look for first, I've suggested following the wiring to the ignition and making sure it's intact.
Can he do anything with the decompression levers?
Any other ideas?
I think these can be hand started, am I right? If so what's the procedure with the decompression levers?

A GM10 with two decompression levers ??????

A 2GM20 perhaps ????

Hand starting procedure is described in the owners/ operating manual, https://www.manualslib.com/manual/1013130/Yanmar-2gm20.html#manual , but essentially lift the decompression levers, crank by hand vigorously while continuing to crank lower the decompression levers.


Absolutely nothing happens when the button is pressed, not even a click or clunk?

Check/ clean/remake all main electrical connections, including the negative

Using a bulb on a couple of leads, rather than a digital multimeter,

Check power is reaching the panel

Check power applied to circuits including stater button when switched on .... check that the warning lights illuminate

Check power out from button when pressed and that power is reaches the small terminal on the starter solenoid.

If all Ok suspect solenoid but if clicks/ clunks then suspect starter motor itself.


Also try power direct from battery + to the small terminal on solenoid. If it cranks then solenoid and starter are OK

if not try cautiously shorting the two large terminals on the solenoid together. If motor spins its OK.

 

[Don107]

If it has a single lever engine control that does both engine revs and forward reverse selection pushing the button in just disengages the forward/reverse function of the lever so it will only alter engine revs and not select forward or reverse

When mine started playing up, occasionally nothing would happen when the starter button was pressed for the first time but over time it started to happen more often until it wouldn't start at all

The things i have described are really easy to do (probably take 10 minutes to do both) and if he does them it will probably fix his problem

Regards Don

 

[steve yates]

Thanks folks, he was at anchor, and is now heading into dallens bay to tie up to the pontoon and have a good play with it, see if he can replicate the issue. I'll text him your replies to try out. Much appreciated, don't want him trashing the new toy before I get a chance to play with it

 

[steve yates]

Vic you may be right, that rings a bell, I forgot there was 2 smaller ones than my own 3gm30.

 

[Don107]

The inline fuse in the engine wiring harness is number 5

Regards Don

 

[Spyro]

As mentioned earlier it sounds like the common problem with gm series. If it happens again a jumper from the pos side of the starter switch to the pos connection on the starter solenoid would hopefully start it. This would confirm an electrical problem. Cleaning all connections and the large wiring harness plugs should fix it. It did with mine. Pressing the button on the gear control doesn't disengage the clutch it just allows the engine to be revved without being in gear. Forget the decompression levers if the starter isn't doing anything.

 

[Sybarite]

Pull the kill handle up and down a few time to prime the pump.
Squirt some Start Pilot or engine oil into the air-intake.

Worked for me. (Volvo 2002)

 

[Spyro]

Pull the kill handle up and down a few time to prime the pump.
Squirt some Start Pilot or engine oil into the air-intake.

Worked for me. (Volvo 2002)

He says he presses the button and nothing happens so I assumed it's not even turning over.

 

[Topcat47]

Common starting problems with the 1GM10 series engines are:-

1. Switch. Jap crap circa 1960. There must be better ones on the market, but I haven't found them.

2. That bloody useless 30 amp fuse and holder in the harness, replace it with something more robust, I had to run a new wire outside the harness to do this...

3. Mine is currently starting fine (summer and warm weather etc) but it helps to turn it over a few times with the decompressor to get the engine running at a decent RPM before dropping the decompression lever. This is also kinder to your starting battery.

4. If all else fails, you may need to rewire the back of the panel. Those lights and their associated transponders on the engine (oil pressure, engine temp etc) can and do present problems eventually.

5. That's fine if it's a simple electrical problem. Mechanical problems do arise and it helps to decoke old engines and pay special attention to the holes in the pre-combustion chamber. I've done two top end overhauls in 15 years and in both cases these were seriously coked up. You may find it impossible to remove the injector and associated gubbins as I did the first time. In this case you need to take the head to a Marine Engineers who may be able to press out the parts for you. In my case the precombustion bit was damaged and I needed a new one, if you're lucky, and it all comes out, you'll still need a new set of copper washers.


My 1GM10 is now 15 years old