R-21 EC keeps dying...

[johnniethek]

Greetings one and all,

I need some technical advice on what might be wrong with the 30 hp Yanmar that is in my 2009 R-21 EC. It has about 1,000 hours on it.

About two months ago, I was trolling in Hood Canal, and the engine rattled and shook, and then just up and died. I would let it rest for a few minutes, it started right up, and then died again after 2-3 minutes. This happened several times until I finally got towed into Pleasant Harbor Marina. I took it to Tacoma Diesel where, at a cost of $650, they went over the whole engine, including adjusting the valves, changed filters, discovered the source of the loud noise coming from under the engine box (one of the bolts that anchored the engine onto the hull had come out), etc., etc. But Tacoma Diesel isn't located on the water, so they couldn't monitor its performance while it was under way.

When I next used the boat off Sekiu last week, it operated great for about two hour (trolling) when it did the same thing. It just up and died. It's not like the engine wouldn't start. Or that it was missing. It just up and died. The oil and battery lights were on when it died, but there was plenty of oil in the boat and it had new batteries. I left the engine off for about five minutes, started it right up again, and it died after about 2-3 minutes. This happened several times before we switched to the kicker motor and came back in.

After checking everything, including the thermostat and fuel pump, we let it sit overnight. It started right up the next day, and we went fishing for three hours until it died again just like it did the previous day and in Hood Canal. Once again, we had to come back to the marina using the kicker motor.

One of the things I discovered since then was that the gas fuel cap was coming unscrewed and popped up during operation. Could the broken fuel cap, somehow, have allowed air to get into the fuel line causing a vapor lock? That might explain why the engine runs fine for a few hours but then shuts down. I bought a new fuel cap/unit that is being installed on the boat today. I think the broken cap may have also allowed water to get into the fuel tank because it no longer stays screwed shut like it used to. I had the tank drained and cleaned, and added new diesel. Could the water that previously had been in the fuel contribute to the problem I am having now? I am (obviously) not a mechanic, but one of my buddies says the water that previously was in the tank may have caused a problem with the fuel injectors...does that seem plausible? If so, what's the remedy?

Thanks, in advance, for any help you can provide.

JtheK

 

[Fisho]

Sounds like water in the fuel or dirty fuel. I trust you have completely emptied your fuel tank and cleaned it? Suggest you also replace the large water trap filter next to the tank with one that has a clear bowl. These engines are almost bullet proof. Under normal circumstances the only thing that upsets them is poor fuel. Good luck.

 

[Newf]

Hi John,, I posted your issue on another forum that I'm on and a guy familiar with diesels but not your in particular had these comments. Hope it helps.


Check fuel tank vent. If it’s plugged or partially plugged. It will pull a vacuum until it can no longer pull the fuel to the injection pump, then it will die. Usually letting it sit will give the tank time to equalize(pressure) and thus allowing the fuel to be sucked out again.

When it happens again, open the fuel tank and listen for the rush of air, then restart and see if you get more then 2-3 min of run time.

Or if it has an electric fuel shut off solenoid, the hold in windings in the solenoid could have a slight resistance causing the solenoid to heat up and fail over time. But this usual is accompanied by a blown fuse or circuit breaker trip depending on application.

 

[Capt’nKarl]

My bet is the problem is in the fuel system and likely the vent on the fuel tank is plugged as previously stated. The fact it runs and then stops then runs again points to a fuel issue. We’re both fuel filters changed during the service? Let us know what you find out.
Karl

 

[RSC]

It sounds like a vacuum issue as others have stated.The vent can certainly be problematic for vacuum issues.
but...
In a previous post that I did on this forum, I discovered after a few hour cruise that water had gotten into my fuel tank when it was up on the lift and the heavy rain had been driving from the stern. The little shelf just below the vent would fill with water and the water would flow into the tank through the vent. The boat had been sitting for a while so over time there was a good accumulation of water in the tank. My clear bowl on the first filter looked fine before I started out so I thought all was OK. After time and pumping fuel the bowl filled with water and clogged the entire system bringing the boat to a stop.The only way I could completely clean the tank of water was to remove it then purge all the lines, replace both filters, purge the injector pump and injectors.. What a pain. Your issue doesn't sound that drastic. But be aware that under the certain conditions there can be water intrusion through the tank vent. Everyone here also recommends a fuel additive called Sea Foam to help with water dispersion.

Good luck and keep us informed.

 

[johnniethek]

Thanks everyone for the feedback.

The vent on the fuel tank and/or fuel shutdown solenoid switch sound like the most likely culprits. I am taking the boat into Gallery Marine in Seattle on Monday for them to work on it. They correctly discovered a problem last year that caused the boat to die -- an elbow-shaped part of the exhaust system was 80 percent clogged with rust. So I am hopeful they will be able to fix this particular issue and I can get back on the water.

I will let everyone know what they discover, and how their remedy works.

JtheK

 

[Capt’nKarl]

I’m sure everyone with a 3YM30 will want to find out what the problem was. Please let us know.
Karl

 

[RSC]

Speaking of the exhaust elbow...That is a critical part in the small Yanmars that surprisingly needs periodic attention and maintenance. That engine is also used in sailboats and I think the sailing crowd is more aware of those exhaust elbow issues. I decided to replaced mine last year after talking to some sailing friends. It was good that I did. It was very compromised with less than 400 hours on the engine. The Yanmar part is cast iron that gets compromised with rust over time. The growth of rust depends on the water that goes through the system and the quality of flushing of the system after engine use. I bought a cast stainless steel direct replacement that is made in Washington State I believe. It is a really nice casting with really nice machining.Hopefully it should be less susceptible to the deterioration associated with water and exhaust heat. It was actually less expensive than Yanmar OEM .

 

[johnniethek]

To one and all,

Thought I would update everyone on the problem and what the solution was.

Turned out to be a clogged fuel pickup tube in the fuel tank.

Turns out there is a screen at the end of the tube that, over time, collected residue. About 3/4 of the residue was wrapped tightly around the screen. But there was an extra flap of residue hanging from the screen. As pressure increased in the tank as fuel was sucked out, the flap would eventually get sucked onto the screen, and the engine would shut down.

That would account for the intermittent nature of the problem. A couple weeks ago, the engine shut down after about an hour the first day of fishing at Sekiu, but the boat ran for about three hours the second day.

The folks at Gallery Marine in Seattle fixed the problem by removing the screen entirely. They said any future residue will be captured by the fuel filter. New models of this engine don't even have a screen at the end of the tube, I was told. If you have an older version of the R-21 EC (mine is a 2009), I would get that screen removed from your fuel pickup tube because it's not needed.

A week ago I had the entire fuel tank emptied and cleaned out in case there was some sediment that had collected there. The folks who did that say there was no appreciable material in it.

So, bottomline, is my tank is clean as a whistle, and the problem of the engine shutting down at various intervals has been solved. I ran the boat for several hours yesterday just to be sure. Now I can make the two-week trip to Barkley Sound later this month that I had been SO looking forward to.

Hope this helps.

Johnnie the K

 

[bob daily]

John, I'm glad you got your problem fixed! Was nice meeting you at the boat dock! At least you had a fun crew to share your problem with, hope to see you and your crew next year. Bob

 

[Gratitude]

I had a similar issue on my Yanmar 110 turbo. It did not die but dropped RPMs significantly chocking the fuel flow. I had to cut a inspection plate into the floor to accesss the pick up line. Later learned the screen is intended for gas not diesel.

Always learning.