1GM10 running issue under load. Help please!

[tillergirl]

It got progressively worse to start, no change in exhaust smoke. What had happened was the engine overheated despite ample water apparently being circulated. It seems the compression was the clue but wasn't as obvious: i.e. it was starting, had some compression, no wheezing. When I lifted the head (not difficult I could see that the water passages in the head (which are small) were clogged and part of the gasket had blown. While at it I ground the valves and seats and replaced the exhaust valve as the valve was starting some deeper pitting. When alll back together the starting was instant and back to full revs. While I don't know the age of the engine I think it was suffering from lack of use - it is described as the 'emergency' engine! The installation was nicely done but a mistake as it is too small (i.e. 10hp v 120hp on the main engine)

 

[coveman]

Is the air filter clean?

 

[winch2]

Interesting read. Hows this for left field. Is there a chance the throttle cable/linkage is slipping when your gunning it? Chk for full tavel?

 

[tillergirl]

Funnily, one of the first thing I did was check for a slipping cable. I would have loved that if it was responsible but for me, sadly it wasn't. But actually doing the head wasn't difficult. Certainly a worthwhile check.

 

[Metalicmike]

Sounds to me like your Throttle cable or another part of that system is sticking.

 

[vas]

good luck sorting it, I have a 2GM that has caused me lots of headache over the last many years, but luckily it's on my 8kva generator, so not that critical...
if you search in pbo you'll find various threads of mine on that.
To keep it short, it was a combo of leaking lift pump (dumped it and replaced it with an electric one) and cross/strip threaded bleeding screws on the godawful yanmar main filter.
Once these were fixed, it's running fine, which is always at 3K rpm and decent load.

cheers

V.

 

[38mess]

Interesting read. Hows this for left field. Is there a chance the throttle cable/linkage is slipping when your gunning it? Chk for full tavel?

See my post #27

 

[bamboozle]

Is the air filter clean?

Yes, air filter is clean. Ive also ran the engine without the filter to confirm that its not an airflow problem.

 

[bamboozle]

Interesting read. Hows this for left field. Is there a chance the throttle cable/linkage is slipping when your gunning it? Chk for full tavel?

Quite sure its not this as Ive been revving the engine using the governor lever on the engine itself to check. Ive checked the throttle cables etc too and all seem to be working properly. The engine revs up no problem in neutral too.

 

[bamboozle]

good luck sorting it, I have a 2GM that has caused me lots of headache over the last many years, but luckily it's on my 8kva generator, so not that critical...
if you search in pbo you'll find various threads of mine on that.
To keep it short, it was a combo of leaking lift pump (dumped it and replaced it with an electric one) and cross/strip threaded bleeding screws on the godawful yanmar main filter.
Once these were fixed, it's running fine, which is always at 3K rpm and decent load.

cheers

V.

Thanks for sharing. I'm at a bit of a loss now as I feel ive checked and re checked everything. I'm going to have another go at the filter housing / bleed screws to check for leaks.

One thing I was wondering though, does anyone know if running the engine the way it is will cause any damage? It feels like fuel starvation limiting revs and not something else, so I would assume that is not causing much in the way of damage or wear?