yamaho 6LYA-STP would not shut down

[lipets]

Yesterday I changed the fuel filters and went to start it, battery was weak engaged the dual battery switch and it started.
But after starting all the engine control gauges turned off, so the shut off button was not working, key on/off not working. Like no power.

I shut the fuel tank valve, kept running

After 20 min waiting for it to run out of fuel I opened the primary filter it was empty, where was it getting fuel to keep running.
Finally with air into that filter shut down strange.

Any other way I could have shut it down?

Any idea what was going on?

 

[Bacchus]

Plenty of fuel in the line and primary / secondary filters to continue to run on. Not sure why/ how air filled the primary filter but will guess the o ring seal is designed for pressure and not as effective for vacuum.

I never had the need but believe you can manually activate the STOP solenoid. Stbd side on engine but I dont have a pic with it called out.
That prompts me to put a trial on my list of things to do. Worth knowing ahead of time exactly what to do.
There is a lever / linkage that should allow manual operation.

 

[jefndeb]

Following as I have the same engine...

 

[DonW28]

Have no idea if it is correct but when I bought my first diesel boat I actually asked one of the local commercial fisherman. His advice was turn off the fuel and cover the air intake. No fuel/no air/no run.


Don

 

[Dougcole]

Not sure if it is exactly the same, but on my 4LHA-STPs you can just push the lever forward on the stop solenoid. It's on the stb side of my motors as well. You can have someone stand at the helm and activate the stop button while you watch the motor to see where it is.


And yeah, if all else fails you can shut off the air flow, but that might be hard to do with a turbo charged motor.


Shutting off fuel flow would be a last resort, because then you have to bleed it to get it started again.

 

[porman]

After anchoring one day my starboard engine, a Yanmar 6LYA-STP, would not shut off with the stop switch. I layed over the top of the engine and found the stop solenoid linkage had come apart. I manually pushed the stop lever to shut the engine down. I found the parts in the bilge and put it back together. Pushing the stop lever is the better way to stop the engine. Then you don't have to wait for it to run out of fuel and no bleeding later.

 

[Todd R]

This may be the solenoid. Bar under pulls back.



Close up

 

[lipets]

Thanks the pic was big help.

I read elsewhere there a relay anyone know where that can be?
I see one next to the alternator???

 

[DavidM]

All Yanmars have engage to stop solenoids as opposed to Cummins who have engage to start. That means once started the engine needs no DC power to keep running. You have to supply power to the stop solenoid to move it into its stop position. Once stopped when you release the switch a spring will return the solenoid to the run position.

So given that your problem started with a mostly dead battery I would focus on what caused that and fix it and see if that doesn't clear up your solenoid problem. You don't have to start it to find out. Just have someone engage the stop switch while you watch the solenoid for proper movement.

David

 

[Comodave]

We had a boat with Detroits in it. One of the stop relays burned out so we had to manually move the solenoid to shut the engine off. It was a PITA but much easier than shutting off air or fuel. We were bringing the boat down the west coast so we didn’t want to take time to search for parts and fix it then. I just had the Butthead that held the stop button down and burned it up go into the engine room and shut the engine down each time, I was hopeful that he would learn something from having to shut it down each time, but alas he was called Butthead for a reason…