What Is this Engine ?

[AussieGeoff]

Hi all.

Little mystery.

My new boat has this engine, supposedly an 18hp Yanmar, which would in theory make it a 2GM20 or some variant thereof.

Trouble is it doesn't seem to look that much like one according to all the pics and even an online manual for the 1/2/3GM series.

I'm told the handcrank arrangement is 'owner built on' but it looks odd even without that, given that huge flywheel/pulley arrangement.

Anyone shed any light? I can't get to the boat for a few months yet, but trying to get everything sorted first, including some spares for the engine.

I've no doubt the design of the GMs has changed over time, but it seems to look very little like one to my (inexpert) eyes.

Any advice appreciated.

AussieGeoff

[S/V Antares]

Any chance of a better picture or a few more. Doutful a GM as intake and exhaust on the same side. Looks like a really old 2GM. Saw one in an old Albin Vega once.

[GordMay]

Yanmar Engine Identification Help
➥ Yanmar Marine Engine Identification Sailboat Supplies, Engine Parts and Boat Parts

Might it be an old discontinued (legacy)?

“SME” ➥ http://yanmar.com.au/media/35489/1sme%202sme%203sme.pdf

Lots of old Yanmar engine information (brochures etc)
Here ➥ Power Equipment Yanmar JCB Mase Gori

[AussieGeoff]

Originally Posted by S/V Antares

Any chance of a better picture or a few more. Doutful a GM as intake and exhaust on the same side. Looks like a really old 2GM. Saw one in an old Albin Vega once.

I'll see what I can do about more pics. Unfortunately I'm half way across the country from the darn boat at the moment.
An old 2GM would make sense. As I said, it's supposed to be an 18hp Yanmar, which would make it a 2GM20(something) near as I can figure, but I can't seem to find an image of a 2GM20 that looks much like it.

Thanks!

Aussie Geoff

[AussieGeoff]

Originally Posted by GordMay

Might it be an old discontinued (legacy)?

“SME” ➥ http://yanmar.com.au/media/35489/1sme%202sme%203sme.pdf

The front flywheel arrangement is almost exactly like that series.

Not sure if it helps, but the serial number is B600216.

If it's a 2SME, that would make it more like 30hp. That would actually makes sense as this is a 12 ton boat, 18hp seems a little light to me.
I'm going to get someone to find the data plate if it still exists, but not sure when that might happen, so still open to suggestions.
I'm looking at all the info you gave me still, thanks for the links, much appreciated.

Cheers

AussieGeoff