YANMAR LIFEBOAT DIESELING/RUN ON

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Mithrandir
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YANMAR LIFEBOAT DIESELING/RUN ON

Post by Mithrandir »

Good day I have a serious question
Our lifeboat engine experienced dieseling/run on during routine testing, the engine didn't even stop when using the stop lever we were forced to cut off the fuel supply of the engine.
Lifeboat's engine YANMAR 3JH25A, You can see the manual online 3JH2 series for yanmar
we cannot determine how this happened.
The fuel injection nozzles had a large hole on the side after the incident.
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JK
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Re: YANMAR LIFEBOAT DIESELING/RUN ON

Post by JK »

I've only seen this happen when the fuel system was contaminated with coolant and made it to the engine, the water blew the side out of the nozzle. Check your fuel supply with water finding paste and see what shows up.
Mithrandir
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Re: YANMAR LIFEBOAT DIESELING/RUN ON

Post by Mithrandir »

First of all sorry for the late reply as we have been busy these past few days. After further testing and checking we have determined that there is a problem with the governor, it is coupled with the fuel pump. we have tried to test the engine again but even though it is in idle the RPM suddenly shoots like crazy, anyways we have reported our situation to our TSI and we have ordered spare parts especially the governor assembly with the fuel pump.
I will try to take tests with the fuel in the life boat. We would just have to wait until the spares arrive until we try to overhaul the engine.
Cheers, and thank you again for the insight.
popeye62
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Re: YANMAR LIFEBOAT DIESELING/RUN ON

Post by popeye62 »

Hello Mithrandir. Yes, it does sound like the governor; sticking rack, seized weights, broken governor link, throttle spring. I am not clear on the holes in the side of the nozzles; it sounds like the nozzles were blocked (low load running), corroded? High viscosity? but you are using DMX/A/Z fuel. If you are in a very cold climate, possibly.
I don't know where you are in your career but here are some basics; apologies if obvious. Lifeboats have a hard life of inactivity. They are run for five minutes once a month? I presume it is fully enclosed so the engine has more protection than an open boat but they do sweat and the boat should be ventilated often with the hatches left open. Get them in the water as often as you can and give them a good run around the dock, they are a crucial LSA and a focus for port state inspectors (L/B deficiencies are in the top 10 list of detentions). Look through your PMS at the reported work orders for the lifeboats, does it give substantive details of the maintenance or does it just say 'Done'? Give details; length of run, load, smoke, starting... anything that will help the next engineer to figure out what the problems are through trends, we love looking at trends. It will also show an inspector that you were proactive. Let other engineers lead the boat crew and make sure all crew, even the ship's cat, know how to start, monitor and operate the engine. Get the boat and the crew to optimum operating condition and keep them there. Make it fun, call it Board of Trade Sport's Day.
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