Starting a diesel after three years on the hard

[nestorph]

Due to circumstances beyond my control, I haven't been able to get my boat in the water for at least three seasons. When I first bought it, it had been in a cradle for two years and the surveyor started up the engine (a Yanmar 2GM20) and ran it for a minute with no problem. Rather than just roll the dice and hope I have the same luck, I'd like to hear from you folks about precautions/prep work I should do prior to re-starting it this year. Thanks in advance!

PS In case you need to know, the fuel has been in the tank the same length of time...

[C420sailor]

Change the oil and filter. If he ran that diesel dry, change the impeller too.

I’d at the very least add a biocide to that fuel.

Crank the engine with the shutoff handle pulled to get the oil pressure up.

[pjShap]

See if you can download a copy of the engine operating manual from Yanmar. For my 4JH4 Yanmar, it specifies cranking the engine for 5 seconds while preventing it from starting, to distribute oil throughout the engine. The 4JH4 has a mechanical fuel stop lever that should be engaged to prevent the starting.

You might also want to ensure oil, filter and fuel are clean.

[chris95040]

Hand crank the engine with a socket wrench, perhaps with the valve cover off to see that all is well.

Last year, after sitting for 3 years, my diesel had a stuck exhaust valve. Rather than take off the valve cover, smother it in lube and try to tap it free, I just cranked really hard with the wrench. I broke a rocker arm and bent a pushrod. Don’t do that!!!

[dadster3]

Mine was 2 yrs. between startups. It fired right up with the existing old fuel in the tank. The only problem was that the raw water impeller shredded for lack of any lubricant or water. Once that was fixed, it fired right up and the wet exhaust spit water just like it should.

You should change the impeller and make sure the batteries are at peak charge.

Unless there is some sort of contamination, diesel fuel doesn't go bad like gasoline, so it may well be fine.

[taxwizz]

Originally Posted by chris95040

Hand crank the engine with a socket wrench, perhaps with the valve cover off to see that all is well.

Last year, after sitting for 3 years, my diesel had a stuck exhaust valve. Rather than take off the valve cover, smother it in lube and try to tap it free, I just cranked really hard with the wrench. I broke a rocker arm and bent a pushrod. Don’t do that!!!

OUCH !
You have my sympathy

[carlheintz]

You need to put fogging oil in each cylinder ... just carefully remove the injectors and spray some in, then replace the injectors. Let it sit for a day. That will ensure that there is enough lubrication to avoid a piston freeze.

[garyfdl]

Originally Posted by C420sailor

Change the oil and filter. If he ran that diesel dry, change the impeller too.

I’d at the very least add a biocide to that fuel.

Crank the engine with the shutoff handle pulled to get the oil pressure up.

While I am debating with C420sailor in another thread, he is spot on here.

If you want a little additional 'insurance', change out the water pump impeller regardless. That way you know it's OK.

[nestorph]

Thanks for the advice. Replacing the impeller has jumped to the top of the list along with changing the oil and filter. Followed by fogging oil...
I have the shop manual so I'll find the fuel stop lever...

[TheLuckyone]

My Volvo Penta MD2B sat for an unknown length of time (at least three years) prior to my acquisition of the boat. It wouldn't turn over by hand; I got a few degrees and then it locked up hard.

Pulled the injectors and let the cylinders soak in a few tablespoons of Marvel Mystery Oil (MMO) for a few days, then bounced the starter on it once (quick flick of the key, fuel shut off). It freed up and I was able to turn it over by hand from that point further.

Your mileage may vary.

Also: take a good look at the rest of the pump when you change out the impeller. Mine had a chunk of impeller embedded in the output side. Prior owner must have missed it during a change, since the one that was in there wasn't damaged.

[Compass790]

Originally Posted by nestorph

Thanks for the advice. Replacing the impeller has jumped to the top of the list along with changing the oil and filter. Followed by fogging oil...
I have the shop manual so I'll find the fuel stop lever...

If the 2gm20 has a decompression lever you are better off to use that to spin the engine up until it gets oil pressure. That way you give the starter & motor an easier life not working against compression.

Personally I wouldn't worry about changing the oil & filter,s just run it if change interval isnt due. I've used 10 year old diesel with no problems but is you have a bod fuel cap o-ring & have got water in the tank could be a different story. Check primary fuel filter after you have run it a few hours.

You can spray a bit of CRC 5-56 or WD40 in air intake whilst cranking ( not decompressed, stop lever on) as well to free rings & lube bore initially.Easier than pulling injectors.
Just my way YMMV

[Shrew]

Unfortunately, fogging oil, fuel stabilizer, diesel biocides all would have been better prior to the 3 year layup. I've shot Mystery Oil into cylinders and let it sit to attempt to ensure there is no cold-welding of the rings.

Replace oil, oil filter, fuel filters, impellor, zincs, and closely inspect all hoses.

[sail sfbay]

Starting up a diesel engine after a 3 year up should not be a problem.........started my sailboat Yanmar and Ford truck diesel engines right up after 3 years (boat was on the hard) after returning from overseas and replacing batteries (truck battery was 14 years old so time to replace anyway).

Diesel fuel will not go bad unless water condensation results in micro organism growth. Suggest checking for evidence of plughing and replace fuel filters, if necessary.

[garyfdl]

Originally Posted by nestorph

Thanks for the advice. Replacing the impeller has jumped to the top of the list along with changing the oil and filter. Followed by fogging oil...
I have the shop manual so I'll find the fuel stop lever...

It may not be in the manual. follow the fuel line from the tank to the engine. The shut-off could be anywhere, but is usually located near the filter, so you can shut off the fuel to change the filter. There could also be one between the filter and the engine. it that's the case, shut off the one closest to the engine.

I think the fogging oil idea is over kill.

FWIW - I am in pretty much the same situation. I just bought a boat that has sat on a trailer for two seasons. Previous owner had it for 22 years. I did my own evaluations/survey. My engine is a 2GM, so the older version of the 2GM20. Opening the compression release, I can turn the engine over, by hand. I cannot do that with the compression release closed, regardless of the handcrank position. That tells me I have compression in both cylinders.

I am going to change the water pump, because the engine has been sitting 2 (well, almost 2 1/2) seasons, and sometimes the impellers will take a 'set'.

I have also pulled the injectors, but not so I could 'fog' the pistons. I did it because the engine is 40+ years old, they have (probably) never been serviced, and, there is some diesel exhaust soot on the transom. The injector shop said they do need to be rebuilt (@ $117 each, including new nozzles). Btw to pull the injectors disconnect the fuel lines and get them out of the way. Loosen the retaining nuts but leave about 1/2 the thread engaged. Then, with the compression release open, rotate the engine by hand, build up some momentum, and then shut the compression release; the injectors will literally 'pop' free. Remove the retaining nuts the rest of the way and you can remove them by hand.

I rotated the engine by hand so that both pistons are mid-stroke and poured about 3 oz of Sea-Foam into each cylinder to soak. This will (hopefully) serve two purposes: first - if there is any still in there when I get back to the boat this weekend, the rings should be sealing - but Sea-Foam is as thin as water (maybe thinner) so if there isn't any, I'm not going to panic/worry about it. Second - the Sea-Foam will get in and around the rings, dissolving the carbon and free them up (if by chance they were stuck) and help with compression.

I also pulled my exhaust elbow and inspected it, again because there was no indication of it ever being done. It was fine.

I also checked the air cleaner - which is actually a silencer. The foam around the perforated inner metal cone was almost gone. The engine has a PCV system, and apparently, the oil vapors from the crank case dissolved the foam which was then 'digested' by the engine. From what I've been able to determine on-line, this is not unusual, the Yanmar 'filter/silencers are junk, and a lot of people run without them. (The old single cylinder Yanmar I had in a Hunter 27 didn't even come equipped with a filter, just an intake tube.)

All of this was a couple hours worth of work, most of which was trying to get the exhaust hose off the exhaust elbow.

When my injectors are ready and my other parts come in, I will go back up (the boat's 2 hrs away) and:

• remove any Sea-Foam that might be in the cylinders and install the injectors.
• check and adjust the valves - again because there is no record of it ever being done and the engine is 40+ years old.
• install the exhaust elbow
• install a new water pump impeller
• install new zincs
• install new belts

At that point, because the boat is on a trailer, I will rig up a cooling water system using a bucket and hose and test the engine.

BTW there is a "Yanmar Marine Engine Owners Group" on Facebook that is a wealth of info (not that CF isn't ).

[Island Time O25]

When I need to run the engine while on the hard I bring a water hose to the cabin with a bucket, disconnect the intake hose from the raw water thruhull and put it in the bucket while filling the bucket from water hose. Thus the raw water pump never runs dry.