2QM15 Yanmar not Run for Years?

[Absolute Kaos]

I am looking at purchasing a 2qm15 that was only run originally for about 200 hrs.. (boat it was in was involved in a fire). Engine was not damaged in fire but boat was totaled. The engine has now sat in a wearhouse since then.

What would be a few things to check before purchasing it. I realize it will most likely need a rebuild but thought I would ask.

[TexSail]

Maybe it's OK. My son is the marine diesel mechanic in the family and we discussed marine diesels sitting up just a few weeks ago. The seals drying out would certainly be somewhat likely. I would have a mechanic look at it BEFORE you started it. It could be that some fogging oil in the cylinders, an oil change, checking the condition of the fuel and maybe turning the engine over for a spell before starting it would be wise. The engine may be fine. I started a tractor engine ( after doing the above procedures) after it had sat 24 years and it ran like a top for years. Don't concede a rebuild until you have a whack at it. JMHO

[Astral Blue]

I woke up a marine Diesel engine (Perkins 4.108) from 25 years of hibernation. Here is what I replaced:

1. rear main seal
2. impeller, oil seal, and water seal on water pump">raw water pump
3. manifold and mixing elbow flange gaskets
4. fuel lift pump (it was leaking)
5. all rubber hoses

At the very least, you will want to pay attention to those items. As far as whether the engine is damaged, you will never know until you run it.

It might be a good idea to get the oil analyzed prior to purchasing it. An oil analysis will give you a lot of information about the engine's condition.

[Absolute Kaos]

I'm going to look at it tomorrow and will post a couple of pics.. Thanks for the suggestions i'll let u know how it turns out.

[DeepFrz]

Make sure you can manually turn the crank through a full 720 degrees.

[Absolute Kaos]

i am getting mixed info on the engine. from another forum.. is this a 15, 18 or 20 horse unit? i have a Laurie Davidson (Dash 34) it's displacement is about 6200lbs. with a waterline of 29.5ft. Anuone know how to calculate the speed at which the 2qm15 will push us at. currently with a 9.9 outboard we do 7knts in flat water.. but as soon as we are against wind and waves we are down to 5.5ish. and outboard comes out of water as we go over waves. This does not help us much either..

[Absolute Kaos]

I should mention that we will be using an SD20 saildrive with it if we purchase it.

[TexSail]

Astral mentioned several more things which should be replaced, I would add a new set of belts. I have a similar engine Yanmar 2gm on a Hunter 33 (displacement around 12500 lbs) and it has enough power - I would think the engine to be plenty for your boat. Good luck, BTW

[Absolute Kaos]

Here are some pics of the engine.. Note it is actually a 2qm20H.. so iquess that makes it a 20hp engine.. should be more than i need to push my bopat at 6200lbs of displacement.. It turns over very easily by hand when the decompression valves are released and is quite hard to turn when the valve are engaged. It looks like it has been stored well.. Just running the specs to see if it will fit into my engine space..

Anyone have any info on this engine, Repair Manuals ect?

Thanks

[Absolute Kaos]

Couple more pics

[charliehows]

my boat is 38', i reckon about 7 tons, 2qm20 pushes it to hull speed (6-7kn) at about 1800rpm, so it ought to be plenty big enough for your boat. Looks bloody brand new, jealous! I'd check the thermostat, too, they tend to rust away over time. Also the seals on the waterpump shaft. Looks great with an intact hand crank chain cover, mines never had one.

[David W]

i realize this is a 2QM20 but we have a 2QM15 in our Crown 34, disp. 10,500 on paper. more like 11,000 in reality. Our 15 hp pushes us to hull speed only with a clean hull but your disp of 6200 lbs should be a breeze with that engine.

[zeehag]

i have a 2qm20h in my ericson--it gets run once per year by my boats caretaker. has less than 150 hours on rebuild. these things are awesome. check rubber stuff and seals .. have a 600 hour overhaul done--will get ye thru anything, as it will be as new. i did that when i bought the ericson--i didnt know how many hours were on engine and previous owner had abused it with gasoline engine equipment--so i had her done as new.

[Alasdair]

I have a 3QM30H in my boat. Th QM series motors are very robust and have a reputation for longevity if looked after. I have the service manual that I will attach if I can work out how to; PM me if it doesn't show up on the thread. With regard to how well this engine will push your yacht; if adequately propped it should do very well. Google Surfbaud Propeller Calculator. I used SURFBAUD to calculate a new prop for my yacht and it was spot on!