Yanmar Diesel dead!?

[fryewe]

If I understand your posts correctly:
- You have had trouble with your starter (specifically failure of the solenoid to operate to apply starting voltage to the starting motor) in the past.
- After sailing recently when you attempted to start the engine you had NOTHING...not even a click of the solenoid.
-You bridged from the solenoid connection to the starting motor connection at the starter and the starting motor ran but didn't engage the flywheel to turn the engine (this is abnormal because this should both move the starting motor gear to engage the flywheel and power up the starting motor).
-You checked for voltage at the solenoid connection on the starter and had voltage (this is normal).
-You checked for voltage at the battery connection to the starter and had no voltage (this is abnormal if you had your battery switch selected to a battery).
-Your battery or batteries are charged (by solar panel).

If all this is correct I would put money on your problem being a failure of your starter. I just don't see how these symptoms translate into water in the engine.

I would:
-Check the oil to see if you can see water in the oil.
-Enlist a friend to hold the decompression lever to relieve cylinder compression and put a large wrench on the drive pulley nut for the generator (cam shaft) and turn the engine over. It has to turn unless it is seized whether it has water in it or not.
-Check the oil for water again.
-Remove the starter and take it to a starter/alternator/electrical shop to be tested.

[RW Sailor]

Originally Posted by fryewe

If I understand your posts correctly:
- You have had trouble with your starter (specifically failure of the solenoid to operate to apply starting voltage to the starting motor) in the past.
- After sailing recently when you attempted to start the engine you had NOTHING...not even a click of the solenoid.
-You bridged from the solenoid connection to the starting motor connection at the starter and the starting motor ran but didn't engage the flywheel to turn the engine (this is abnormal because this should both move the starting motor gear to engage the flywheel and power up the starting motor).
-You checked for voltage at the solenoid connection on the starter and had voltage (this is normal).
-You checked for voltage at the battery connection to the starter and had no voltage (this is abnormal if you had your battery switch selected to a battery).
-Your battery or batteries are charged (by solar panel).

If all this is correct I would put money on your problem being a failure of your starter. I just don't see how these symptoms translate into water in the engine.

I would:
-Check the oil to see if you can see water in the oil.
-Enlist a friend to hold the decompression lever to relieve cylinder compression and put a large wrench on the drive pulley nut for the generator (cam shaft) and turn the engine over. It has to turn unless it is seized whether it has water in it or not.
-Check the oil for water again.
-Remove the starter and take it to a starter/alternator/electrical shop to be tested.

Yes that is pretty much it, with some little changes though:
The starter now seems to work (as you said it was replaced before) the only thing that doesn't make sense here is that it turns on bridging on the solenoid but not on turn of the key (maybe because it's not engaging the flywheel?)
The Batteries are also getting charge from shore power at the moment, so they are both full as can be.
But as far as I am concerned I am pretty sure the problem is not the starter but more the engine itself since that is the part that just wouldn't move at the moment and also stops the starter...
But that is me - not really much experience with Diesels...

[fryewe]

"The starter now seems to work (as you said it was replaced before) the only thing that doesn't make sense here is that it turns on bridging on the solenoid but not on turn of the key (maybe because it's not engaging the flywheel?)"

If the starter turns when the terminals are bridged but not when the key switch is turned the key switch is faulty or the circuit is broken somewhere...perhaps even at the starter.

A solenoid is an electromechanical device...when you turn the switch you apply electricity to a coil and the magnetic field that the current causes then moves solenoid parts to (1) shut contacts to apply the main starting power to the starting motor and (2) slide the gear on the starting motor along its shaft so that it engages the flywheel gear. The starting gear disengages after the engine starts.

If the starting motor is turning and the engine is not turning then the gear on the starting motor gear is not engaging the flywheel gear or the starting motor shaft is broken. The starting motor is a series motor and if powered without the load of starting the engine it will speed up rapidly and will "whine" due to bearing noise while running at high speed.

The most likely causes of not engaging the flywheel gear are:
- broken or worn teeth on the flywheel gear. If teeth are broken and these teeth are at the location the starting gear is trying to engage the engine won't be driven. You can diagnose whether it is caused by broken teeth by turning the engine by hand to expose other flywheel teeth to the starting gear. If the symptoms persist then it is highly unlikely that broken teeth aren't your problem.
- worn teeth on the starting gear. This could be due to age and use or due to repeated attempts to start with the gear not fully engaged.
-solenoid failure.

When the starting motor is energized and the gears engage when you bridge the circuit on the starter if the engine is hydrolocked with water or seized you will simply hear a click and a loud hum (not the whine of high speed machinery) when the starter operates. The hum is due to the motor NOT turning and if left powered up more than momentarily the motor will overheat and will be damaged.

As far as a broken circuit goes...some care is needed when connecting a starter to the external circuit. If the terminals are indiscriminately tightened without holding the terminal nut that affixes the coil connections to the casing the connections of the coils to the terminals can be broken internal to the starter.

[fryewe]

One last possibility...

Sometimes the starting gear and flywheel gear can become "bound" or jammed due to misalignment or high friction. In that case the starter can hum and the engine won't turn due to the load on the starter being to high and stalling the motor.

I still think the simplest next step for you is to pull the starter and have it checked. Once the starter is pulled you can check the flywheel teeth for damage with the engine in place.

To check for a faulty solenoid circuit at the starter you can simply remove the solenoid wire from its terminal and then use a multimeter to check for continuity of the circuit from the terminal to ground. The resistance should be very low...I don't know what the exact value should be but probably less than an ohm (mine is 0.25 ohm).

[RW Sailor]

Alright, so there is a new update:
Didn't really do anything different from before, tried bleeding the engine again (low pressure part) and it seemed like it was ok before so basically I did nothing, BUT:
I tried starting again by key and it fired up, but then I was back at the old problem:
After about 5 minutes running fine it just stops on me. I could start it again right after (bit of smoke involved in that one) and it died on me again about 30 seconds later....
ideas?

[fryewe]

Sounds like an air leak in the fuel supply to me.

And an intermittently bad switch key.

Of course I could be wrong.

[RW Sailor]

Originally Posted by fryewe

Sounds like an air leak in the fuel supply to me.

And an intermittently bad switch key.

Of course I could be wrong.

Switch key in fact was bad, but I changed it a few days ago, so that can't be an issue right now...

[RW Sailor]

just double checked and couldn't find any loose connections... any other reason comming to anybodies mind? and how would a leak in the connection (or a fault connection in the fuel line) cause the smoke on startup? (which btw was NOT occuring just now...)
And even without bleeding the line beforehand I could just start it up again for a couple of minutes - seems not to make sense if it ran out of fuel before?

[fryewe]

Your small engine will run a long time on a little bit of fuel. It will also shut down if a little bit of air gets into the fuel line.

Air can get dissolved in the fuel and then later come out of solution and form small air bubbles. Air bubbles can rise to higher points in the fuel line and be displaced with fuel such that the fuel will be pumped and the engine start and run until the air is moved to the injectors.

Many times it takes repeated primings and relatively long run periods to get all the air out of the system.

If you have a small leak you will likely have the most trouble with the initial start of the engine after a long period of shutdown.

[Rakuflames]

Originally Posted by Liam Wald

Many years ago (1980's) I had a Yanmar 12hp single cylinder. I found out after it died that this model (due to the extreme vibration caused by the imbalance of one cylinder) requires frequent attention to the head bolt torque, They seem to shake themselves loose opening a channel for sea water to find it's way into the cylinder.
When the cylinder fills with water and comes up on the compression stroke many things bend and/or break.
If that is what happened to your engine and it will cost $3k+- to rebuild, I would seriously consider just replacing the motor with a 2 cylinder.

I had an old 12 hp raw water Yanmar in this boat. I had many people work on it but it kept overheating, completely unpredictably. It was completely unreliable and I repleced it with a 20 hp Yanmar.

It runs wonderfully and dependably. The engine was only 1" longer than the old one. Everything from dip stick to impeller is much more accessible, making it much easier to maintain the engine. I love the thing.

[RW Sailor]

Originally Posted by Rakuflames

I had an old 12 hp raw water Yanmar in this boat. I had many people work on it but it kept overheating, completely unpredictably. It was completely unreliable and I repleced it with a 20 hp Yanmar.

It runs wonderfully and dependably. The engine was only 1" longer than the old one. Everything from dip stick to impeller is much more accessible, making it much easier to maintain the engine. I love the thing.

Which one is that? Seriously I've had trouble with the engine from the beginning even though it was rebuild in 2007, but it never ran for more than 1 hour without some issue and fixing up so it is getting really annoying.
And so slowly I am looking into replacement options. Also did you get to sell your old engine or just scrap it? And where do you buy marine diesels?
I am currently looking into options but high up in the ranking are also electric engines...

[mcerdos]

It sounds very much like a solenoid issue. You should be able to put a screwdriver across it to see if the starter works (it will spark - be careful).

Also, have you checked the stop lever and switch (is it stuck)?

[RW Sailor]

Originally Posted by mcerdos

It sounds very much like a solenoid issue. You should be able to put a screwdriver across it to see if the starter works (it will spark - be careful).

Also, have you checked the stop lever and switch (is it stuck)?

Yes, I've played that game before as well, that's actually meant when I said I bridged the solenoid... so the starter does work (and did spark)
The stop levers are in a good position.
Also the engine does run for short times before it stops again (just nothing I want to even remotely rely on really...

[mcerdos]

Based on the fact the engine will run and then stops (by itself). It is 90% a fuel issue. Does the engine chug to a stop (drop rpm) or is it as if you stop button with an immediate stop? A chug also indicates fuel problems.

Start at the beginning of the fuel system and ensure you have fuel all through the supply.

Do you have a self priming engine or does it have a manual pump? If you have a pump, you may need to bleed the system repeatedly to remove all the air. Bleed the engine at ALL injectors.

Have you checked for a fuel leak? If it leaks - even a drop - air will get in the system. Some of the most common leaks are due to dirt on the seal of the fuel filter. Put a large diaper pad (available at pet stores or Wal-Mart in the pet section) under the engine while it is running to check for leaks.

[RW Sailor]

Originally Posted by mcerdos

Based on the fact the engine will run and then stops (by itself). It is 90% a fuel issue. Does the engine chug to a stop (drop rpm) or is it as if you stop button with an immediate stop? A chug also indicates fuel problems.

Start at the beginning of the fuel system and ensure you have fuel all through the supply.

Do you have a self priming engine or does it have a manual pump? If you have a pump, you may need to bleed the system repeatedly to remove all the air. Bleed the engine at ALL injectors.

Have you checked for a fuel leak? If it leaks - even a drop - air will get in the system. Some of the most common leaks are due to dirt on the seal of the fuel filter. Put a large diaper pad (available at pet stores or Wal-Mart in the pet section) under the engine while it is running to check for leaks.

Hello, I just had Badsanta over (maybe you wanna say something too)
So the system was bleeded a couple of times (and one more just now). The stop is more rapid, so basically as if stopped by button.
The one concerning thing is, that I can't turn the engine at all - in neutral with starter taken off it is still too stiff to even turn in a tiny bit. I think that is the main problem...