Yanmar 1GM10 - advice?

Severnman said:
Get your replacement exhaust elbow from ExhaustElbow.com. US company, delivered quality product much much cheaper than Yanmar in a few days. No connection; just a happy customer.
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Just had a look at the site, quite impressed at US$99 for stainless.
Will keep for future (i.e. soon) reference.
 
northcave said:
Thanks for that! Come on everyone, what are your engine numbers and years? :D
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I actually asked a question about numbers and ages only last week, but the thread fizzled out:):)

According to the distributors, EP Barrus, my engine number 06378 is not on their data base, but they suggest it would be about year 2000. That's a little later than was suggested by the person who sold it to me.
 
Rob_Webb said:
I think that's pretty normal, the black is usually unburnt diesel from the engine slightly overfuelling until it reaches full speed (engine and boat). In the same way that if you acelerate sharply from idle to say 50% throttle, you will see a small amount of black until the engine settles at the new fuel burn rate.

If you never get any black at full throttle it's possible your throttle cable could do with a tweak adjustment as you may have a few more potential revs in the engine that you aren't obtaining with your throttle lever wide open.
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Thanks for that :)
 
northcave said:
In a prospective boat is a Yanmar 1GM10. A common engine for boat built in the mid 80's I gather.

This particular engine has no history other that the engine number (04033).

Can someone with some knowledge let me know a few things please. If it is original and therefore about 25 years old, is it likely to be on the away out or will it continue to provide useful service if maintained well?

What specific things can I look for when sea trialing it and is an engineers pressure test worth doing?

Many thanks for any advice in advance.
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Some people swear by them but usually they have just bought a new one! I have always bought fixer-uppers as to be honest I enjoy restoring things more than actually using them and to be honest I'm not impressed in the slightest with the 1GM10.

(1) Firstly anyone who knows anything about engineering will know that grey cast iron is strong in compression but weak in extension. In spite of this they make the front pulley out of grey cast iron and bolt it onto a tapered shaft. The result is that the pulley often splits through the key-way, FAIL! When fitting these pulleys be sure to use engineering adhesive and don't tighten the nut too tight. Curiously Ruggerini made a similar gaffe with the flywheel on some of their engines.

(2) The next demerit is the lubrication system. Now whilst a yachtsman eulogised over what a brilliant design it was having the oil filter at the front, personally I'm not so sure. The problem is that the filter relies on extremely vulnerable external oil pipes and banjo unions. The oil pipes appear to be mild steel and after sitting in bilge-water they rust away and crumble for a pastime! Allegedly banjo unions are made to ISO standard sizes so it should be possible to buy new ones from a hydraulics specialist. As to the pipes "Kunifer Perrenic Auto" is probably the best material to use as it is stronger than copper. It is an alloy of copper, nickel and iron hence the name Cu Ni Fer. Some soldering or brazing will be required to upgrade these pipes but when £50 and £70 per pipe is asked for at the chandlers.........

(3) The third demerit of these engines is that they are raw water cooled. This means that one is stuck with having to run the engine at a low temperature in order to try to prevent hard-water deposits in the water jacket. Deposits still occur of course and one engine that I bought is virtually a basket case because of this. The post-mortem showed calcium deposits in the thermostat housing and a blown head gasket. Sea-water then trickled into the aft-tappet-tunnel and rusted the tappet to the block. The result is an engine that almost turns two times but then locks-up. Possibly a big hammer will fix it. At one time freshwater conversion kits could be bought from a company named Martec.

(4) The fourth demerit is the exhaust elbow. This has a baffle to deflect the injected water down the exhaust pipe. The exhaust elbow is made from cast iron and it is common for the baffle to rust away. When this happens sea-water can get injected into the exhaust port. It may still be possible to buy aftermarket upgraded exhaust elbows made from Stainless Steel but these are not cheap.

IMHO all the parts for these engines are exceedingly costly for what they are, for example a gasket set for a Land Rover Discovery 300 Tdi engine costs less than a gasket set for the 1GM10 and a set of four new standard pistons (complete with rings, gudgeon pins and circlips) for a Discovery 300Tdi can be bought for less than £100. When £70 is asked for a set of 1GM10 piston rings one does have to wonder just what is going on but they will probably trot out the phrase "Limited market".

The good points are that the 1GM amd 1GM10 are the smallest and lightest diesel engines that are commonly available in this class. Farryman used to sell the Yellow River Star which is lighter but when a friend wanted to buy one (new) it appeared that the agent couldn't be bothered to order one.

Alternatives in this size were the Petter Mini Six (mixed metals plus sea-water caused problems) and the BMW D7 based on a Hatz industrial engine. The Hatz relies on splash lubrication and the built-in generator was extremely iffy so these are best avoided unless doctored.

Nowadays marinised industrial engines seem to be the way to go. The weight and size are hardly any greater but the parts are less expensive.

Raw water cooling is IMHO best reserved for boats that are only used on lakes and rivers
 
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davey said:
(2) The next demerit is the lubrication system. Now whilst a yachtsman eulogised over what a brilliant design it was having the oil filter at the front, personally I'm not so sure. The problem is that the filter relies on extremely vulnerable external oil pipes and banjo unions. The oil pipes appear to be mild steel and after sitting in bilge-water they rust away and crumble for a pastime! Allegedly banjo unions are made to ISO standard sizes so it should be possible to buy new ones from a hydraulics specialist. As to the pipes "Kunifer Perrenic Auto" is probably the best material to use as it is stronger than copper. It is an alloy of copper, nickel and iron hence the name Cu Ni Fer. Some soldering or brazing will be required to upgrade these pipes but when £50 and £70 per pipe is asked for at the chandlers.........
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I replaced those two pipes on mine with hoses from Pirtek. They made them on the spot and the total cost was about £35

(4) The fourth demerit is the exhaust elbow. This has a baffle to deflect the injected water down the exhaust pipe. The exhaust elbow is made from cast iron and it is common for the baffle to rust away. When this happens sea-water can get injected into the exhaust port. It may still be possible to buy aftermarket upgraded exhaust elbows made from Stainless Steel but these are not cheap.
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The OEM Yanmar exhaust elbow is stainless steel. I have one of the aftermarket ones (www.exhaustelbow.com) because it's around one third of the price of the Yanmar one.

IMHO all the parts for these engines are exceedingly costly for what they are, for example a gasket set for a Land Rover Discovery 300 Tdi engine costs less than a gasket set for the 1GM10 and a set of four new standard pistons (complete with rings, gudgeon pins and circlips) for a Discovery 300Tdi cam be bought for less than £100. When £70 is asked for a set of 1GM10 piston rings one does have to wonder just what is going on but they will probably trot out the phrase "Limited market".
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Absolutely right. If it's any consolation, Yanmar parts in mainland Europe are even more expensive. You can get them for half the UK prices in the US, but they aren't allowed to sell to th UK, so you need someone to forward or bring them for you. I got a complete top end overhaul kit (head, precombustion chamber, thermostat and all gaskets) in the US for around 2/3 the cost of the head alone in the UK.
 
davey said:
Some people swear by them but usually they have just bought a new one! I have always bought fixer-uppers as to be honest I enjoy restoring things more than actually using them and to be honest I'm not impressed in the slightest with the 1GM10.

(1) Firstly anyone who knows anything about engineering will know that grey cast iron is strong in compression but weak in extension. In spite of this they make the front pulley out of grey cast iron and bolt it onto a tapered shaft. The result is that the pulley often splits through the key-way, FAIL! When fitting these pulleys be sure to use engineering adhesive and don't tighten the nut too tight. Curiously Ruggerini made a similar gaffe with the flywheel on some of their engines.

(2) The next demerit is the lubrication system. Now whilst a yachtsman eulogised over what a brilliant design it was having the oil filter at the front, personally I'm not so sure. The problem is that the filter relies on extremely vulnerable external oil pipes and banjo unions. The oil pipes appear to be mild steel and after sitting in bilge-water they rust away and crumble for a pastime! Allegedly banjo unions are made to ISO standard sizes so it should be possible to buy new ones from a hydraulics specialist. As to the pipes "Kunifer Perrenic Auto" is probably the best material to use as it is stronger than copper. It is an alloy of copper, nickel and iron hence the name Cu Ni Fer. Some soldering or brazing will be required to upgrade these pipes but when £50 and £70 per pipe is asked for at the chandlers.........

(3) The third demerit of these engines is that they are raw water cooled. This means that one is stuck with having to run the engine at a low temperature in order to try to prevent hard-water deposits in the water jacket. Deposits still occur of course and one engine that I bought is virtually a basket case because of this. The post-mortem showed calcium deposits in the thermostat housing and a blown head gasket. Sea-water then trickled into the aft-tappet-tunnel and rusted the tappet to the block. The result is an engine that almost turns two times but then locks-up. Possibly a big hammer will fix it. At one time freshwater conversion kits could be bought from a company named Martec.

(4) The fourth demerit is the exhaust elbow. This has a baffle to deflect the injected water down the exhaust pipe. The exhaust elbow is made from cast iron and it is common for the baffle to rust away. When this happens sea-water can get injected into the exhaust port. It may still be possible to buy aftermarket upgraded exhaust elbows made from Stainless Steel but these are not cheap.

IMHO all the parts for these engines are exceedingly costly for what they are, for example a gasket set for a Land Rover Discovery 300 Tdi engine costs less than a gasket set for the 1GM10 and a set of four new standard pistons (complete with rings, gudgeon pins and circlips) for a Discovery 300Tdi cam be bought for less than £100. When £70 is asked for a set of 1GM10 piston rings one does have to wonder just what is going on but they will probably trot out the phrase "Limited market".

The good points are that the 1GM amd 1GM10 are the smallest and lightest diesel engines that are commonly available in this class. Farryman used to sell the Yellow River Star which is lighter but when a friend wanted to buy one (new) it appeared that the agent couldn't be bothered to order one.

Alternatives in this size were the Petter Mini Six (mixed metals plus sea-water caused problems) and the BMW D7 based on a Hatz industrial engine. The Hatz relies on splash lubrication and the built-in generator was extremely iffy so these are best avoided unless doctored.

Nowadays marinised industrial engines seem to be the way to go. The weight and size are hardly any greater but the parts are less expensive.
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Epic. Sadly it was two years ago I needed the advice :)

Since then I bought the boat with the 1GM10 and it has been wonderful. For me it's been bomb proof and easy to service.
 
Regarding black smoke, the cause may not be the engine at all. Before even lifting a spanner please check the propeller for old rope, seaweed or most common of all, barnacles!

Grey smoke is usually injector trouble. On some engines a pop pressure of 1800 psi is no use at all. A new injector spring will need to be fitted and the pop pressure adjusted to between 2200 and 2400 psi. The higher pressure creates smaller droplets which burn faster. A decent diesel injector service station will be able to do this job for a modest fee.
 
Lots of advice - I had the 2GM20, before replacing it with a 3YM20.

Significantly, Yanmar appear to still be producing the 1GM10, as the smallest engine in their sailboat range.
As (together with Briggs & Stratton) it's probably the most popular engine ever produced (most go into Asian FVs) we don't need a self-appointed "expert" to pass off his prejudices and recommend a singularly inferior conversion of a static industrial engine for a genuine marine design.
From Yanmar engineers, the weakest point is the cylinder head coolant passages, either blocking or leaking into the cylinder.
 
Of course a 20 year old engine is suspect but then so is everything else on the boat that is 20 years old. If it were all like new then you would be paying a like new price.

Previous posters have highlighted the risk areas. If the engine seems to run ok, then the key area to check is whether lube oil is coming out in the exhaust water. If the exhaust elbow goes and you dont notice, then the hot salt water can get back in the engine and knacker the cylinder head hence the oil in the water. Otherwise the eng ine is a good unit as you would expect from yanmar.

If you buy the boat budget on an immediate exhaust elbow replace to be safe.
 
Yanmar 1GM10

Spyro said:
That can also be caused when engine is over propped or a dirt prop or hull. Also can be a a sign of a blocked exhaust elbow.
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Great engine. I too have a wee bit grey/black soot at full revs or when the engine is over loaded. The engine is not over propped and does not have a blocked exhaust elbow. After investigating this over ten years there is no answer. Beware of getting caught up in work/expense when a wipe of the transom once a month with soapy water can solve the problem.
 
Maintenance schedule requires that the exhaust elbow (£150+vat+incidentals) is changed every 2 years otherwise the elbow may rust through. Then, you write the cylinder head off (£700+vat+incidentals) and this can lead to the bore flooding with sea water and requiring a re-bore so as a DIY job it cost me £1500 for the parts and the re-bore and hone!
 
JumbleDuck said:
That's a neat trick, bearing in mind that it's made of stainless steel.
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My not "rust" - but it does corrode and can cause the damage the poster suggests. However they last far more than 2 years and it is not difficult to inspect regularly and reduce the chances of corrosion.

But of course you already know this, but its late on a wet and windy night when pedants often escape!!!
 
Tranona said:
My not "rust" - but it does corrode and can cause the damage the poster suggests. However they last far more than 2 years and it is not difficult to inspect regularly and reduce the chances of corrosion.
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All true.

But of course you already know this, but its late on a wet and windy night when pedants often escape!!!
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<Laughs maniacally and slinks back into the trees>

Incidentally, my www.exhaustelbow.com aftermarket elbow is holding up fine, I think, although I shall be taking it off this winter to give it a Good Hard Stare.
 
bluebosunsmate said:
Maintenance schedule requires that the exhaust elbow (£150+vat+incidentals) is changed every 2 years otherwise the elbow may rust through. Then, you write the cylinder head off (£700+vat+incidentals) and this can lead to the bore flooding with sea water and requiring a re-bore so as a DIY job it cost me £1500 for the parts and the re-bore and hone!
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Without questioning that this can prove expensive if the elbow fails, the schedule in my manual simply says 'inspect every 250 hrs.) rather than replace every 2 years so it depends on your mileage ,whether you have sail as primary propulsion,and also the condition when you acquired the vessel.
 
tom_sail said:
That was a very useful reply, thanks. I was little worried by mine producing black smoke on full throttle buts it's a small amount just a haze of grey/black smoke.
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If you have grey smoke there is a possibility that the Injection Pressure is a bit on the low side. With virtually all "mechanical" diesels 1800 psi is no good as the fuel droplets are too big and they don't have enough time to burn completely. A good diesel service station will test the pop-pressure of the injector for a small contribution to their tea swindle and a really good test station will adjust the pop-pressure for free if one is a good customer. The difference that a few hundred psi extra makes is truly amazing as at 2200 to 2400 psi the fuel gets atomised properly. Severe overheating often weakens injector springs so it is always possible for jellyfish or plastic bags to spoil the running of the engine.
 
Re the cleaning of the exhaust elbow in the hope of prolonging its life. No you don't do that at all! After the first season, if it lasts that long, bin the OEM part or save it in case one wishes to sell the engine at a later date. Before binning the part buy a North American non-genuine-replica made from 316 stainless. These elbows are far superior to the OEM part and they cost less!
 
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davey said:
Re the cleaning of the exhaust elbow in the hope of prolonging its life. No you don't do that at all! After the first season, if it lasts that long, bin the OEM part or save it in case one wishes to sell the engine at a later date. Before binning the part buy a North American non-genuine-replica made from 316 stainless. These elbows are far superior to the OEM part and they cost less!
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Though note that the OEM ones are also stainless. I had one of the US ones and it was very good, particularly at around 1/2 of the OEM price.
 
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