My Yanmar 2gm20 has never been used, sat dry in a garage for 8yrs. Will it work?

[tobyfaulkner]

I bought the engine recently, it's never had fuel or oil put in it. Sat with a plastic bag over it in a dry garage, all bits still in box.
It's about a 2005 model, I'd like know if anyone with a good knowledge of boat engines whether it will be all good to go or if there's a good chance of corrosion inside somewhere.

 

[yoda]

If was me I would remove the glow plugs, squirt in some light oil and then see if the engine will turn over by hand. If so then filling with oil and water, connecting it up on a test bench and running it could be the next step. You could also remove the sump and have a look before you add fluids. No reason why it shouldn't work but difficult to know until you look or try.

Yoda

 

[Birdseye]

I would have thought there might be some corrosion particularly externally where there has been condensation. But its unlikely to be an issue that will stop the engine working. You could also have problems with seals and will certainly need to replace the water pump impellor which will have taken a set. But I would expect the engine to work and probably without a problem.

Depress the compression release lever, fill the sump with oil and turn the engine over on the starter until you get oil pressure. Let the starter motor cool then turn the engine over for a further 20 secs to make sure there is oil everywhere. Then start it.

One possible issue. I once bought a new GM10 to install in my boat and when it started there was no oil pressure. It was simply that all the oil had drained from the pump which needed priming. Spoke to Barrus and they said run the engine at medium revs for 30 secs - nerveracking with the oil pressure alarm going. But that worked and the pump primed. It wouldnt prime at idle revs. Apparently I was OK doing this because there would still be the oil from manufacture between components and of course the oil pump circulates oil - its the hydrodynamics that keeps bearing surfaces apart.

 

[mtb]

The engine would have been test run at the factory even just building the engine requires lubrication so there must have been oil in at some point which may mean or could mean the oil used carry's contaminates and any acids present may eat away at the bearings, engines laid up even just for a short time ideally should have the oil changed to a storage oil with anty corrosive elements

re condition

It depends on the moister in the shed, also if it went from hot to cold then you might expect rust inside, eight years is a long time
First take the rocker cover off and pour oil over the rocker assembly, if you are able to move the engine on its side it would be a good idea to fill the oil filter to give things a chance.
If it hasn't seized I'd turn it over by hand with the decompression levers for as long as it takes to see oil pumping at the rocker shaft
The piston rings may be stuck all the rubber items re seals may have hardened / valve stem seals / crank shaft seals fuel pump diaphragm and so on

If you want to sell it I may be interested

cheers
mick

 

[jerrytug]

Don't turn it, more than you need to gently, but inspect the crankshaft mains and the big ends, and the camshaft bearings, for rust, in addition to the precautions above. It's worth it otherwise you are risking the crankshaft. That's what I would do, it's easy on the bench..

IMHO you can be 100% certain there will be rust in it.