"Freshening Up" Yanmar at 2000 hours

[Hudson Force]

Originally Posted by sailorchic34

..............

On rusty bits, passivate with phosphoric acid and repaint. Just brush on the phosphoric acid, no need to rinse.

Ok, I'm all for this, but didn't you repaint your engine pink or lavender? ....or was that some photoshop trick from a past post? ....or then maybe I have a faulty memory!

[Dockhead]

Originally Posted by sailcrazy

Speaking of "freshing" up your engine....although we had never done it, a mechanic we employed after having some issues while cruising in Turkey "strongly" recommended we should run our engine up to max/near max RPM for 15-20 minutes after every 4-5 hours of motor-sailing. We typically run our 4JH-TE (55hp, turbocharged) at 2000-2300 RPMs while under way, and the max RPM is 3600. We had never heard that advice before, and have had some mechanics say..."absolutely, you need to do that", while others have said absolutely NOT...Would you take your car and run it at full throttle every 5-6 hours of driving?.. I've asked every mechanic we've come across just to get their opinion We have been doing it, and based on the carbon particles on the swimm platform and the smoke that comes out of the exhaust...maybe it's not a bad idea? But I've never heard of another cruising boat do it. Any thoughts?

Haven't you read your manual???? It says right there to do it.

And I do!

I think the purpose of it is to burn out the deposits and soot and condensatio which forms when you run at low RPM. Remember, diesels are not like petrol engines in that they have no throttle plates -- so at a given RPM, the volume of air which goes through them does not change -- only the amount of fuel is varied. In petrol engines, the petrol and is always in more or less the same proportion, just the volume of the mix is varied by creating a partial vacuum in the intake tract with the throttle plate.

The result of this is that diesels run at low loads will have much lower temperatures in the combustion chambers -- because a little bit of fuel is being burned, but a whole lot of air is flowing through. This is the same reason why diesels don't warm up if you just idle them without a load (and I hope you know to never do this when they're cold! Very bad for them!).

So Yanmar believes that harmful crap accumulates at low RPM and load, and you need to burn it out regularly. Who are we to argue? You should always do what the manufacturer tells you -- they don't just pull these things out of their somethings.

I enjoy my little full throttle jaunts. I run mine up right to the redline, which with a clean bottom and calm water gives me up to 10 knots of boat speed.

I also run my engine at full throttle in reverse every time I anchor, as the final test of the set of the anchor when it seems to be well dug in. This serves the dual purpose of fulfilling Yanmar's dictate, and applying the strongest pull you can on your anchor.

After doing this, be absolutely sure not to just shut the engine down. You will coke the turbo bearings. Run it at low speed with no load for a couple of minutes to cool off the turbo bearings, before shutting it down.

[Dockhead]

Originally Posted by svfraidknot

i have 2 yanmar 4jh2e on my boat still going great i have a brand new PSS shaft seal for a one inch shaft i cannot use ,, i have 300 invested in it here in panama ,, my v drive clearance on my cat gives only 4 inches to work with a pain even to change a packing gland ,, if you change yours and it is one inch shaft perhaps we could work a trade ???

I wish! A one inch shaft on a 25 ton boat with 100 horsepower? Are you joking? Mine is 1.5", several sizes bigger than that.

[MBWhite]

Originally Posted by Dockhead

When I bought that boat, it had 830 hours on it. Now, five years later, it is pushing 2000.

replaced all of the injectors,

My draft program is as follows:

1. Adjust valves (never done it before; the Yanmar dealer who serviced the engine when I bought the boat said no need to bother, but now I'm wondering whether I should have taken that advice).
2. Repair or replace exhaust elbow. The massive stainless steel unit now has a pinhole leak.
3. Replace all engine hoses (I already did this once; when I bought the boat).
4. Replace all belts (ditto).
5. Remove the heat exchanger, clean out thoroughly, inspect. The engine runs rock steady at the thermostat opening temp (80C) no matter what the load, but after 2000 hours I figure it's time for this. Do I need to carry a spare?
6. Ditto the engine oil cooler, transmission oil cooler, intercooler.
7. Check injection timing.
8. Wash turbo with the special, expensive Yanmar snake juice.
9. Drain coolant, flush out with distilled water, replace with new coolant.
10. Replace motor mounts as necessary to eliminate knocking at idle.
11. Clean out vents from antisiphon loops.
12. Replace start batt. Which is 13 years old!!! Has lasted this long because its work is trivial, and it's not used for anything else (start system is completely separate from house batts, and I have two separate alternators). But I don't want to push my luck!



Last question: I don't much like the fact that the Yanmar silver-blue-gray paint is failing in places and going over to rust. Is this external rust any concern? Some rigid steel pipes are rusting which makes me nervous. Should I do something with this, or don't worry about it?

My 2 cents:

1) As mentioned, just check the clearances and if in spec, leave be.
2) Remove the manifold and decide a plan of action after it has been cleaned and inspected.
3) Inspect the hoses, but if not cracked or bulged (showing the internal fiber reinforcement is breaking down) consider them good.
4) If you have replacement belts aready, just inspect them and leave them alone unless they are showing cracking or excess wear/glazing if they are V-Belts. If they do have some cracks then yeah, replace them and keep them as spares.
5) Sounds good but no need to carry a spare, just have a good inspection on it.
6) I'd say ask this of a local Yanmar dealer who is knowledgeable on how these engines are in your local climate.
7) Timing sounds good, leave alone for now.
8) Do whatever Yanmar recommends
9) Skip the distilled water, tap water is fine.
10) If they are broken, fix them but otherwise leave them alone.
11) Cleaning is always good, you don't need to wait 1,000 hours to do it.
12) Your call, but probably not a bad idea.

Rusty metal won't hurt to get a wire brushing then a primer with iron oxide and followed with paint.

Since you have already replaced your injectors I wouldn't even worry about them at all.

Likewise your 24V alternator, those things are built like tanks but even if it were to fail you have an additional alternator so all the more reason to leave it alone for now.

As mentioned earlier, I too have seen or had to repair a lot of previously sound machinery that someone decided to improve, update, or make more reliable.....

Good luck!

Mark

[transmitterdan]

Dockhead,

Definitely replace the bellows of the dripless shaft seal per PYI recommendation (you can go an extra year without much risk). It should be done every few years.

[sailorchic34]

Originally Posted by Hudson Force

Ok, I'm all for this, but didn't you repaint your engine pink or lavender? ....or was that some photoshop trick from a past post? ....or then maybe I have a faulty memory!

Oh your memories perfect. Yes I painted my engine last year in a lovely rich purple with pink injector and oil lines. It's so hard finding pink engine paint.

I did however brush on some phosphoric acid on the rust bits, prior to painting, while it was so ever conveniently located in the cockpit.

[chuckr]

may i redo this thread a bit please.. we have a 4jh3e 56hp that came on our jeanneau when we bought her new in 2003.

i have kept to something of a fair maintenance schedule and have absolutely no issues with the engine. but we now have 4,700 hours and have just a bit of smoke when we start her. i was think to do a bit of pm on the engine before the upcoming sailing season as we will probably be motoring a bit (lack of sailing wind in the med) and i do not need any issues.

as i can not do a lot due to shoulder surgery i thought i would have a local mechanic, who is good, do a bit of a go over on the engine but not too much as i can do some on my own next year when we winter over in turkey.

understand that i did some pm stuff when we had a fuel tank cleaned this fall by euromarine in dubrovnik but only 150hr type stuff plus a bit.

any thoughts on what you would have done that would be of the more important issues.

[Dhillen]

Originally Posted by chuckr

may i redo this thread a bit please.. we have a 4jh3e 56hp that came on our jeanneau when we bought her new in 2003.

i have kept to something of a fair maintenance schedule and have absolutely no issues with the engine. but we now have 4,700 hours and have just a bit of smoke when we start her. i was think to do a bit of pm on the engine before the upcoming sailing season as we will probably be motoring a bit (lack of sailing wind in the med) and i do not need any issues.

as i can not do a lot due to shoulder surgery i thought i would have a local mechanic, who is good, do a bit of a go over on the engine but not too much as i can do some on my own next year when we winter over in turkey.

understand that i did some pm stuff when we had a fuel tank cleaned this fall by euromarine in dubrovnik but only 150hr type stuff plus a bit.

any thoughts on what you would have done that would be of the more important issues.

Having the same engine and being equally happy with it, some of the things I have done to "freshen" it up were:

Checking the exhaust elbow. After 10 years, depending on the design, it may be a good idea to replace it.

Same for the exhaust hoses; look for wear or any soft spots, and inspect the hose clamps; carry clamp spares.

Valve adjustment if you haven't done one in a while.

I am assuming your regular preventative maintenance includes timely replacement of belts, filters and impeller.

I also carry around a spare starter just in case I am marooned somewhere far away and mine fries (happened before on another boat).

Cheers.

Dhillen

[chuckr]

Originally Posted by Dhillen

Having the same engine and being equally happy with it, some of the things I have done to "freshen" it up were:

Checking the exhaust elbow. After 10 years, depending on the design, it may be a good idea to replace it.

Same for the exhaust hoses; look for wear or any soft spots, and inspect the hose clamps; carry clamp spares.

Valve adjustment if you haven't done one in a while.

I am assuming your regular preventative maintenance includes timely replacement of belts, filters and impeller.

I also carry around a spare starter just in case I am marooned somewhere far away and mine fries (happened before on another boat).



Cheers.

Dhillen

thanks -- we carry spare hoses and solenoid and fuses and now an alternator but good idea on the starter. valve adjustment is a good idea and i think i will have him pull the injectors to make sure they are ok.

[MarkSF]

Originally Posted by MBWhite

My 2 cents:

1) As mentioned, just check the clearances and if in spec, leave be.
2) Remove the manifold and decide a plan of action after it has been cleaned and inspected.
3) Inspect the hoses, but if not cracked or bulged (showing the internal fiber reinforcement is breaking down) consider them good.
4) If you have replacement belts aready, just inspect them and leave them alone unless they are showing cracking or excess wear/glazing if they are V-Belts. If they do have some cracks then yeah, replace them and keep them as spares.
5) Sounds good but no need to carry a spare, just have a good inspection on it.
6) I'd say ask this of a local Yanmar dealer who is knowledgeable on how these engines are in your local climate.
7) Timing sounds good, leave alone for now.
8) Do whatever Yanmar recommends
9) Skip the distilled water, tap water is fine.
10) If they are broken, fix them but otherwise leave them alone.
11) Cleaning is always good, you don't need to wait 1,000 hours to do it.
12) Your call, but probably not a bad idea.

Rusty metal won't hurt to get a wire brushing then a primer with iron oxide and followed with paint.

Since you have already replaced your injectors I wouldn't even worry about them at all.

Likewise your 24V alternator, those things are built like tanks but even if it were to fail you have an additional alternator so all the more reason to leave it alone for now.

As mentioned earlier, I too have seen or had to repair a lot of previously sound machinery that someone decided to improve, update, or make more reliable.....

Good luck!

Mark

You are wrong about the tap water. Using tap water, effectively, uses a little of the corrosion inhibitors up, right away, neutralising the mineral content. So after going to all that trouble to change the coolant, because you want to make sure that the corrosion inhibitors will work for as long as possible, you're going to start by shortening their life? For the 99 cents that distilled water will cost you, do it right.

[MarkSF]

Originally Posted by sailorchic34

Oh your memories perfect. Yes I painted my engine last year in a lovely rich purple with pink injector and oil lines. It's so hard finding pink engine paint.

I did however brush on some phosphoric acid on the rust bits, prior to painting, while it was so ever conveniently located in the cockpit.

Surely Rustoleum is entirely suitable, and comes in all kinds of colours.