Yanmar 2GM Tune Up Kit

dmax · Feb 14, 2023

There really isn't a tune-up kit per se as diesels don't have spark plugs or points or anything. Things that you'll want to do:
* Change the oil and filter
* Flush and change the anti-freeze coolant
* Clean up the exterior of the engine and look for any leaks
* If there is an air filter, get a new one. Some can just be cleaned.
* Look at your fan belt, make sure it is tight (approx. 1/2 inch deflection when pressed), if it's worn at all, replace it.
* Examine all the hoses, plan on replacing all of them unless they look newish to you (can be done over time)
* Change your raw water pump impeller and examine the condition of the pump externally and internally
* Change the transmission fluid
* Open up your heat exchanger, if you see deposits, you'll want to remove it and clean it/have it cleaned. Replace the gaskets.
* Take a look at your motor mounts, rubber should be intact, not cracked etc. You should be able to move the engine a bit (i.e. the mounts should flex). If they are original, it's probably time to replace them.

Alan Gomes · Feb 14, 2023

justustoo said:
I've seen some kits, but they seem pretty sketchy. This is a raw water cooled engine so I'm thinking some Salt-Away in a recirc cycle might be warranted. On the fence as to whether to try and start the engine as-is and then change out the filters after a trial run, or to do so immediately and hope there isn't too much gunk in the tank. Good advice on the transmission fluid and motor mounts. I hadn't thought of them as being in the equation at all.

Regarding using Salt Away (or whatever) to clean out the engine passages: I'm not sure how you are planning to do your "recirc cycle." But you might want to take a look at the documentation for the 2GM to see how the cooling system works on that engine. If you simply fire up the engine and stick the pump intake hose into a bucket of Salt Away, the water will likely just pump through the bypass and out the exhaust, bypassing the engine internals. I say "likely" because it depends upon the state of the thermostat, which in turn depends upon the engine temperature, of course.

In order to guarantee that the water will flow through the engine passages, you need to remove the thermostat and pinch off the hose that runs between the the T and the bottom of the thermostat housing. This will ensure that the water will flow through the engine's internal cooling passages.

If you look at a drawing of how the cooling system is plumbed you'll see what I mean. I've attached it for your convenience.

kloudie1 · Feb 14, 2023

Couple of other things: check and set valve clearance and replace the anodes after the salt away. Since that Yanmar is raw water cooled, it will have anodes.

dmax · Feb 14, 2023

Because it sat for five years, I would be inclined to change out the fluids and filters before starting it.

Crusty Ol Salt · Feb 14, 2023

dmax said:
Because it sat for five years, I would be inclined to change out the fluids and filters before starting it.

BINGO

RoyS · Feb 15, 2023

Be sure to crank the engine with the decompression lever held open until the oil pressure alarm stops. This will ensure that all the engine bearings are lubricated before starting.

Benny17441 · Feb 15, 2023

5 years on the hard, that fuel is gunk. Pump out whatever fuel is left on the tank and put in about 10 gallons of fresh fuel plus some "Clear Diesel" fuel and tank cleaner (Tractor Supply). Replace Fuel filters, change oil and filter, bleed air out of the fuel lines and attempt to start. Have a fully charged battery to assist in engine cranking speed and open up the throtle lever to about 3/4. Once you get the engine running check the exhaust to make sure cooling water is circulating. Once you get the engine running well replace the raw water impeller and transmission fluid. It might be a good idea as part of the tune up to check and adjust the valve lash.

Claude L.-Auger · Feb 16, 2023

RoyS said:
Be sure to crank the engine with the decompression lever held open until the oil pressure alarm stops. This will ensure that all the engine bearings are lubricated before starting.

Whether in the water or on the hard, be sure to shut off the water intake and possibly disconnect the hose from the impeller pump to the engine (or remove impeller pump belt). If that engine cranks without starting for anytime longer than a few seconds, water will be inserted in the cylinders through the opening exhaust valves, creating hydro-lock.

Alan Gomes · Feb 16, 2023

Claude L.-Auger said:
Whether in the water or on the hard, be sure to shut off the water intake and possibly disconnect the hose from the impeller pump to the engine (or remove impeller pump belt). If that engine cranks without starting for anytime longer than a few seconds, water will be inserted in the cylinders through the opening exhaust valves, creating hydro-lock.

That must be one dinky water lift muffler. While one does have to be careful not to cause the water lift muffler to overflow, it would certainly take a good deal longer than "a few seconds." It would take prolonged cranking to do so.

Tally Ho · Feb 16, 2023

Alan Gomes said:
That must be one dinky water lift muffler. While one does have to be careful not to cause the water lift muffler to overflow, it would certainly take a good deal longer than "a few seconds." It would take prolonged cranking to do so.

Maybe not so long if it is already full. I have never check to see how much water is mine after shutting down my engine. I assume it is mostly full.

Greg

Alan Gomes · Feb 16, 2023

Tally Ho said:
Maybe not so long if it is already full. I have never check to see how much water is mine after shutting down my engine. I assume it is mostly full.

Greg

Fair point. Still, it should definitely take more than "a few seconds" of cranking to make it overflow and cause hydrolock.

RoyS · Feb 17, 2023

Yes, fair point about hydro-lock. Remember to always race your engine for a second to blow coolant water out of your exhaust system when you shut down your engine. Also, when winterizing remember to drain your muffler.

Tally Ho · Feb 17, 2023

justustoo said:
Good stuff here. I had spoken before with the yard manager about the fuel tank (it is the original as far as I can tell, and it's full). His suggestion was to pump the tank dry, and then if the fuel looks decent, filter it and throw it in my home heating tank. I may do this as my nose tells me that there is some porosity going on, but not yet enough to create a substantial leak. So a replacement should be happening sooner rather than later. Hydrolocking the engine has been probably the foremost concern on my mind. I think once I get the starting process down, it'll be much less of a concern.

You could pull the impeller the first time you are trying to start the old girl, so you don’t flood the engine ( and leave the thru hull closed). Then you can crank as much as needed and you also won’t burn up the impeller with the thru-hull closed. This assumes you are going to try to start it in the water.

if it was me, I would be inclined to do a fluid changes you plan to do, get a fresh battery installed, remove the impeller, and try to start it on the hard. If/when she starts, you can shut her down, install a new impeller, put the boat in the water and be confident she will start. You could run it for a few minutes on the hard without damage.

If the weather is cold, heat the air at the air intake (hair dryer or heat gun works good) to help it start. Not sure that starting fluid or ether is recommended, but heating the air is very helpful to get a cold diesel to start.

Good luck with it. Hope you are out sailing in the spring!

Greg

Yanmar 2GM Tune Up Kit

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