Opinions on Yanmar 3gmd

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Senior Member
Jul 6, 2014
western australia
Hi guys,
Iam interested in purchasing a FD boat with a Yanmar 3 GMD ('97 year)diesel motor.

If any members here have had experience with this size/model engine I would appreciate their comments. I am interested in hearing of your opinions - both good and bad concerning reputation, parts availability -anything really that you want to vent your speen about !!

For whoever is interested in what boat it's in :-
The boat is a Fibreglass FD motor sailer. Length 8 metres (24ft) waterline and beam of around 2.5 mts.
Total displacement of 1500kg (3307lbs)
It is balasted with 500kg of lead.
There is a warranty with engine and 10 hrs engine hours (sea trials).


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I had a sailboat, Erwin 34', with a Yanmar 3GMF. Very good engine, I did nothing to it in the 6 yrs I owned it other than change the oil.
Thx Tim,
That's a recommendation if ever I heard one !!!
I guess what my main concern about this engine is the :cry:"raw" seawater cooling.
I wouldn't imagine the diesel engine in my Toyota Landcruiser would last very long with salt water flowing through the cooling system.
Was wondering how long/many hours one could expect before some costly replacements parts were called for.
They are in many Albin 25s. Qwners all love the engine.
I had a 3HM35F (34hp) and it was a good engine.

That boat dosn't look much like a motorsailer. Is it Scandinavian? They like aft cabins.
I had that engine in one of the sailboats I owned. The engine was great but the raw water exhaust did clog up once and caused the engine to get hot. Did not hurt the engine. had to remove the exhaust manifold and the elbow and clean. No problem after that. Worse case I would think if this did happen the parts would not be to bad if you had to buy new. That is as long as you catch the overheat. The engine control panel on mine had a very loud alarm to let you know about the overheat.
By the way it was totally sea water cooled and it was an 1983 engine and this happened in 1998 or so. sold it in 99 for a bigger boat.
Hi Manyboats,
I did use a liberal dose of licence when I called it a motorsailor. Of course I should of known those knowing better would find me out.
She was built in Australia to a Finnish design and was produced with a 7 metre mast.
Anyhow that's really beside the point of the posting. As im a pretty much a newbie to anything but outboard motors I know squat about these "Raw seawater" cooled inboards. Was kindda concerned what life I can expect from a 'raw' motor before corrosion etc.
Attached is a pic of her with a mast and sail as produced


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As far as life expectancy I had a perkins 4-108 in the next sailboat and it was all raw water cooled. It was a 1982 and it was still running great two years ago when I sold the boat. No issues at all with the cooling on the engine. It was used alot. Not sure if it was left setting for long period if that would affect it but that affects fresh water cooled also. I was sceptical also but it never let me down.
My 3 GMF was freshwater cooled with a raw water heat exchanger. Probably what the F meant.
Engines designed for sea water direct cooling, like Yanmar and Volvo- tend to have pretty long service lives. They put enough meat in the castings to handle the expected corrosion. How long??? Good question. On the Volvos, little coolant passages clog and force you to take it apart to clean. Things like that.

How old is the Yanmar? Make sure you run it a good while at full power to make sure it does not overheat. If it stays cool with good water flow out the exhaust, at least you know cooling system is not clogged.

Take an oil sample to check for sodium- that is your hint that sea water is getting past the head gasket into the oil. Kiss of death, there, as a new gasket probably won't seal either due to corroded castings.
Like the boat a lot and the engine too. Other than an OB I wouldn't mess w a seawater cooled engine but many run them. I flush my OBs every chance I get too. My inboard diesel has her seawater cooled heat exchanger on a bulkhead just aft of the engine. No seawater on or in the engine at all. I made a point of installing my engine w that feature. My Yanmar was fresh water cooled but leaked seawater down onto the fuel injector shaft from the heat exchanger in the exhaust manifold and caused it to become hard to turn. That experience led me to the remote heat exchanger in my present boat.

The mast and sail on that boat is most likely a steadying sail. Looks like it could make use of it too. I was thinking about a steadying sail well aft to reduce swinging at anchor.
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I like those Finn 8's. Unusual layout with the forward cockpit, but they'd be great as long as you didn't get a wave over the bow.

Re: the raw water cooled engines - I am just re-powering my boat after the 32 year old volvo md17 has finally rotted out. Its been great up until now, and I'd rebuild if parts were readily available. This engine was purpose built as a raw water cooled engine with a very heavy block.

I don't have any Yanmar experience, but double check on the year of that engine. I think the 3GMD's were built in the early 80's, and discontinued about 1983, so that 1997 date may not be correct.
HI Auscan,
Nice to hear from you again hope you are in Aussie enjoying your break.
The engine numbers supplied to me were - 02462 97 - which lead me to the assumption that the 97 was year of production. The owner tells me that the boat is 1999 built, so that kindda fitted.

Ski, The owner tells me the boat engine and g/box warranty from the reconditioning has expired from time however the motor has only 12 hours use (sea trials) he claims - like breaking time I guess?
So i'm thinking would a motor with limited life (block and water jackets suspect)be put to the expense of reconditioning.
My real issue is never had this type of engine before, never had a boat like this before. Wanted to hear opinions from members on this brand and type of motors reliability.
Only had dinghys with outboards previously that were flushed with fresh water immediately after use.

Manyboats, I was thinking along the lines of a mast mounted on the front top of the aft cabin and sail over the cabin, like whats seen on the rear of a ketch or yawl. There's an large opening at back of aft cabin where I could control the boom/ sheets etc.
Do you think it would sail into the wind with the mast and sail so far backwards from the centre of the boat?
Just being able to sail downwind and steadying would be nice.
Will post a pic of the rear opening of aft cabin where I trim from.The rear hatch folds back a sectin of the lower roof also.
She has a cute 'derriere' eh?

regards Brett


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HI Auscan,
Nice to hear from you again hope you are in Aussie enjoying your break.
The engine numbers supplied to me were - 02462 97 - which lead me to the assumption that the 97 was year of production. The owner tells me that the boat is 1999 built, so that kindda fitted.

regards Brett

Yes- Had a nice break back in Adelaide. Back to work tomorrow to pay for my engine replacement.

Check out this webpage Yanmar Marine Engine Identification Sailboat Supplies, Engine Parts and Boat Parts
for Yanmar model number details.
If it's a 3GM30 it could be a later model, as they built them up until 2005.
It appears that 3GMD is a 22hp produced 1980-83. The owner says it's the original motor - seems a bit odd too me that the engine is 17 years older than the boat?
Might have to dig deeper with the serial numbers - 02464 97
regards for link


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Yes I agree. She looks slack in the stern and somewhat full in the bow. A fish form hull. Probably should have the stick and rag fwd.

Can't see much of the bottom but if she is FD only about 15hp would be needed. Almost looks like a flat bottom in a way. Is it possible she's a dory? With seawater cooling running the Yanmar at 1/3 load may be good to keep her cool and minimize the cyl salting. May have been a plan.
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Here's a better shot of her bottom ;)......... LOL , nice curves actually:) with a rather sharp keel throughout and being more pronounced toward the rear.
I read somewhere long keels help a boat track/steer better undersail ?
A sail positioned over the aft cabin with boom extending to rear hatch would with main sheets and block attended to from rear hatch would be perfect.
Looks like sits nice and level in the water judged from the second pic.


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Nice boat. I really do like her. And she sits on her lines very nicely. This is the kind of boat I should have. Never seen one like this. She should be in the "Interesting Boats" thread. The helm is far fwd so you may not like the ride at times. I'd love to watch her wake from the cockpit. Is the engine half in the cockpit and half in the cabin? And is she settled on her trailer in the usual manner or is this a temporary arrangement. Launching bow first w an inboard seems problematic. So when are you going to take her?
The helm is aft!! I think!!!
Mr. mb. To my eye she's sitting in a stern launch position on the trailer unless she has a prop on the bow.
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Hmmmmmm ......... Oh ....... I looked for the helm and only see what looks like a helmsman's chair in the cabin. Or perhaps the helm hinges down from the overhead of the cabin. Do you think he steers from the aft end on the cabin? At first I was having trouble w the bow and stern ... It's a "unusualness" boat. Whatever .. I like it a lot but for me I'd wish she was bigger and w helm amidships.
My 37hp engine would drive this boat fine even if she was 37'.

Haha ... I had it right in the first place. Look again. She's bow in on the trailer. I think I like her even better now.

Thanks Ski. Going to optomoligist tomorrow.
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Brett, a very nice boat indeed. Love those scandinavian designs. A mid or bow cockpit might be a good choice for part-time fisherman and people who have to carry goods to their island homes.

Here:Korsö-Marin are more modern, beefed up boats with the cockpit at the "wrong side".
I can't tell from bow and stern. Each time I look at the boat, my mind changes.
She's a double ender in the pure sense of the word !!!
Steering is from front of aft cabin, so basically you are just shy of amidships. (pic 1 looking fwd)
Engine bay is immediately forward of aft cabin entrance. (pic 2 overhead view from fwd/cuddy)
pic 3 engine bay looking aft
pic 4 '' fwd (new S/S fuel tank)
pic 5 '' overhead
She loaded onto trailer front first - as all ladies are !!

Other than up to me to fly across to Queensland and view it, go for drive, and then find a marine surveyor.
Then the money haggling fun begins ?? NOT !!!
regards Brett


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Manyboats...........this pic I forgot to include but is the same boat i'm interested in. I post it expressly for your enjoyment. I have come to realise from my short time on T/F you have a great admiration of boat wakes - this one will surely give you a morning bon*r. :thumb:


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hi Auscan,
Well I caught the 'redeye' across OZ and have been in Queensland for 3 days and had a good look at her on the trailer. On Friday was offered an overnight fishing trip to Fraser Island to feel her at sea and experience what sleeping and living on board might be like. The owner didn't go, just a mate of his so I got a' little 'more impartial opinion perhaps - maybe !!!

I made an offer on her with condition that a few minor repairs were taken care of and my offer was accepted.

I can tell you she flies along with her 3gm Yanmar 3600 rpm - 22hp. We obtained 9.5 kts @ 2800 rpm. I was a was more than impressed, one very happy camper :smitten:with that performance at under 3 litres an hour for entire 7 hour engine hours trip - less than a jerry can full.
Have included 2 pics - first is on return trip at 9 knots and other is aft cabin plenty of sleeping room for 2.
regards brett



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Thanks for all the sharing and interaction. All I can say is BUY IT. But I'm not there look'in at it and don't know your needs so good luck plugg'in all the variables together but I hope you buy it. Don't loose sight if how small she is and size has little to do w overall length.
Hello All,
Was searching for anything to do with a Finn8 and stumbled across this site and thread. My boat is a Finn8, recently acquired, and I noted with enjoyment the confusion the double ended design has caused. Nothing new there. The boating community around where I live has responded in a similar fashion. I have thought about painting Port and Starboard different colors. Now that would give cause to some serious commentary!

Regarding the real topic of this thread, I have used raw water cooled Yanmars for many years and am not disappointed. At the risk of stating the obvious, with raw water cooling the number one requirement is to check the sacrificial anodes. Yanmars often make access to the anode plugs difficult, but the more often you do it, the easier it gets.
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