Yanmar alarm

[Sandhurst]

Hi. I have just purchased my first boat which has a 57hp Yanmar Diesel engine.
On starting the alarm sounds then after a few seconds comes on again loud ear piercing sound. It was diagnosed as a faulty sensor on the fuel pump which was replaced with a new one.
It was okay for a short while but the problem has returned.
Water is circulating through the filter and Oil, temp etc are okay.
I was advised it was safe to disconnect the alarm as it was an anomaly/ with the sensor. I have tried extra revs on starting to no avail. Disconnecting to me is not a fix so I’m looking for some advice please.

 

[Dellquay13]

You may get more replies if you repost this question on the motor boat forum, it's a little bit sailboat-centric here on pbo reader to reader. Especially so if it is the new 4JH57 common rail engine in your Shetland27i.
If you don't have the Yanmar manual, try looking for one online to see what the FAQs say about engine alarms, and what the full list of alarms are, then repost with any further info.

 

[VicS]

The owners manual can be found at
https://www.yanmar.com/media/global...on/operationmanual/JH-CR_OPM_0AJHC-M00011.pdf

I don't see any mention of a sensor on the fuel pump but there is a water in fuel filter / water separator alarm.

Check for water in the water separator
Disconnect the sensor If that silences the alarm then the trouble is probably a faulty sensor.

Low engine oil pressure. high coolant temperature and, where appropriate, water in sail drive will also trigger the audible alarm

 

[Sandhurst]

That’s great thank you

 

[Sailfree]

I fitted an overheat alarm in the exhaust as the best way of ensuring you notice a problem.

Mine is a 75hp turbo yanmar