Starting a stored Yanmar Engine

[bbalan]

Hi all.

I have a 20 year-old Yanmar 4JH2TE with 3,800 hours. The boat has been on the hard for 20 months and is now back in the water. I did not expect to be in the yard for so long so I did not prepare the engine for such a long storage. I did flush the raw water system with fresh water when we first went in the yard and I’ve turned the fly wheel by hand several times. Other than that, nothing.

Is there anything I should do before I try to start the engine?
Thanks very much.
Bruce
s/v Migration
Phuket, Thailand

[LeaseOnLife]

I would

• turn it over by hand a few more times
• check oil and coolant
• bleed the diesel supply including the injection pump
• make sure the engine stop solenoid works
• press engine stop button while cranking the engine until oil pressure builds up
• release engine stop button and let it start

Dirk

[a64pilot]

I'd pull the injectors and put a teaspoon or so of very light oil, Marvel Mystery oil or mixture of kerosene and motor oil etc. in each cylinder, then leaving the injectors out, spin the engine with the starter, observe normal oil pressure and just let oil circulate through for a few seconds. Then re-install the injectors and crank her up.

You did either inspect and or replace the raw water impeller? Also anytime your spinning a motor without intending it to start, close the thru hull to prevent hydraulic locking the motor

[a64pilot]

Once you have an hour or so on the engine and it's been fully heated up, change the oil

[model 10]

The absolutely best way is to pre-oil it. It's a pain unless you are set up for it. The idea is you tap into the oil system somewhere (oil psi switch), and pump oil through the system. A good hand pump/ squirt can, a few fittings and a quart of thin oil. Or build a pressure system with compressed air.. Depends on how important it all is to you.
As soon as it fires it will need oil.

[Scout 30]

Does keeping the rpm's low for a few minutes help?

[MBWhite]

Originally Posted by Scout 30

Does keeping the rpm's low for a few minutes help?

Absolutely. There have been huge improvements in engine durability over the past 30 years so do not take this as being relevant to todays engines, but back then it was estimated that 50% of an engines wear occurred in the first 5 minutes of running.

Since then there have been huge improvements in both engine metallurgy and lubricant additives. Remember when even as recently as the 80's it was quite a rarity for a car to have 100,000 miles, now most all will go 200,000 and quite a few will go a LOT more than that. But it is still good practice to let an engine warm up gradually first. If you think about your repairs, it is usually not things like valves and piston rings that get replaced but more like water pumps and alternators and maybe a head gasket. These items still benefit from a gradual warm up to get the moving surfaces lubricated and heated evenly.

In regards to pre-oiling, it is extremely beneficial to do this. As mentioned earlier, about the easiest way to do this is to crank the engine with whatever shutoff system activated so it can't start and then let it build up pressure. It does not need to be over 5 pounds or so, just get the needle moving a bit. Then let the starter wait for a few minutes so the oil up in the valve train has a chance to drip down on the valves and stuff. I'd like to do this at least twice with 5-10 minutes between cranks. You can always find something else to fiddle with while you are waiting. If you can pull the injectors easily great, and give each cylinder a 1/4 teaspoon of oil but sometimes pulling old injectors causes more issues than it is worth. You can also squirt WD40 or other spray lubricant into the intake and turn the engine over a few times to help get some into the top end. If you have a decompression lever on your engine great, just use the starter but if your particular engine has a fuel shut off solenoid then just turn the engine slowly by hand as vigorous cranking may cause it to start.

Hope that helps!

[SkiprJohn]

Originally Posted by a64pilot

I'd pull the injectors and put a teaspoon or so of very light oil, Marvel Mystery oil or mixture of kerosene and motor oil etc. in each cylinder, then leaving the injectors out, spin the engine with the starter, observe normal oil pressure and just let oil circulate through for a few seconds. Then re-install the injectors and crank her up.

You did either inspect and or replace the raw water impeller? Also anytime your spinning a motor without intending it to start, close the thru hull to prevent hydraulic locking the motor

As soon as the engine starts, open that thru hull to get the seawater to the impeller or you'll chew it up.

[bbalan]

Thanks to everyone for the great tips. Really appreciate it. I'll tackle this today or tomorrow and let you know the results.
Thanks again.
Bruce

[bbalan]

Hi All,
Yesterday I fired the engine up. There was a terrible screeching sound and then it fell of it's mounts and caught on fire....

Just joking

All went well. The advice I received here was good. Though I know I should have pre-oiled the system, I didn't have the equipment or time. As for putting oil in the cylinders, that would have been great. However, I agreed with MBWhite that it might lead to other problems pulling the injectors. I couldn't spray WD40 in the intake because of the turbo. So, knowing it was probably causing more wear than other methods, this is what I did:

1. Checked fluid levels
2. Hand cranked about 10 times
3. Checked the impeller (which was in great shape). Put in a little synthetic grease between some of the vanes to help it out when it was running dry.
4. Made sure it had fuel (I didn't bleed everything as there was still fuel in the lines).
5. Pulled the stop and turned the engine over until I saw movement on the oil pressure gauge. I have a mechanical as well as the Yanmar electric gauge. I used the mechanical as the electric takes to long to move. That was probably about 10 seconds.
6. Let it sit for 10 minutes.
7. Repeated step 5 above.
8. Let it sit for 10 minutes.
9. Pushed in the stop and started. It caught and then died which told me I didn't have quite enough fuel. I have an electric pump that I can put inline before the primary filters via some valves. I turned that on for about 5 - 10 seconds Then turned it off and switched the valves back to normal. (I never have to bleed the system if I do this).
10. Started. And it caught immediately.
11. Opened the cooling water seacock!
12. Checked for water coming from the exhaust.
13. Listened to it purr. Sounded great and ran super smooth.
14. Checked for leaks.

I'll change the oil and filters now.

Thanks again for the quick responses.
Cheers,
Bruce

[Cheechako]

I would probably change the impellor. They seem to take a set if left real long. ....and of course will come to pieces at just the wrong time... additionally leaving bits and scraps thoughout your cooling system...:>)

[SkiprJohn]

Congratulations!

Isn't that a great feeling?

Now just make certain you have good clean fuel too. I don't know if any said that but don't use old contaminated fuel. If your tanks are suspect at all just get in there and clean everything well.

[model 10]

Originally Posted by Cheechako

I would probably change the impellor. They seem to take a set if left real long. ....and of course will come to pieces at just the wrong time... additionally leaving bits and scraps thoughout your cooling system...:>)

You need to change the impeller also.

[Scout 30]

My neighbor bought a boat about a month ago & he hired a fuel polishing company. I spoke to the guy when he was out here & he told me that with old diesel all they do is run it through a 30 micron filter. It doesn't go bad like gas but you need to get rid of any water or stuff growing in it.

[Cheechako]

Originally Posted by Guy

You need to change the impeller also.

Yeah... that one too!