My boat, with a Yanmar 3GM30 raw water cooled diesel engine, is about to remain on the hard stand for 18 mths to 2 years.
I'm currently emptying the 110 litres diesel tank and using it up in my car. I figure leaving it in the tank for 2 years may introduce problems to the fuel system.
So some questions that come to mind are :
(1) do I drain the whole system including fuel pump, filter, lines right up to the injectors?
(2) if I do (1) then what is the best method of draining everything?
(3) how do I prevent bacterial growth within the empty fuel tank?
(4) is a better choice to leave the tank full with an additive of some sort to preserve the whole fuel system for 2 yrs?
(5) if (4) is the better way then which additive to buy?
(6) do I drain the raw water from the engine block ?

I've checked the engine service manual but there is nothing written about long term storage.
All suggestions welcomed.

fuel tanks that are left empty get condensation in them which then causes rust and crap to form in the tank.
Best thing to do is keep tank full.
Replace all fluids and lubes just before you park it up so everything is clean and lubed with the best stuff.
When its time to get it going again you will have to drop all fluids replace with new stuff then after a short time drop it all again.

Engines are living creatures, they need a regular heart beat to keep going.

Can you pull it out? Good chance to give it a good overhaul?

One thing is for sure. Before you lay it up, run the engine up to temp, shut down, drain the sump, fill with fresh oil and run it up to temp again then shut down.

Re:- Fuel system. Turn off fuel supply valve/cock to keep it sealed during lay up. Drain fuel tank etc.

After lay up, change oil before start up and hope for the best. Being a Yanmar all should be OK. If it is raw water cooled, I would be draining the cooling jackets, flushing with fresh and then sealing the system with fresh water inside to eliminate oxygen and keep seals moist.

Yanmars are tough and fairly forgiving.

Belive, any metal can by stored indefinitely providing no air accessing critical parts.
Air inlet and outlet have to be air tight and I would put some silica gel bags. / air breather too /
fresh oil good quality, for cooling system use standart car antifreeze mix. U set for decade.

Charriot said..
one more, before you top up fuel tank put at least a litre methylated spirit to control moisture.
methyl mixes with water, might control algie but most importantly , it floats on surface and blocks the air
getting to the fuel .

You forgot to mention to ditch that fuel concoction before running the motor