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Re: YANMAR 4JH3-HTE Diesel Engine RPMs drop and then it quits

Ian Shepherd
 

Michael,

I had a fuel starvation problem with my Yanmar, but it was in starting, not whilst it was running, though I seldom use the engine other than for leaving and arriving at the dock. It was due to air in the engine fuel filter housing. I had changed the engine fuel filter, and whilst all looked well after bleeding, the problem was traced to the O-ring at the bottom of the filter housing. Having change the O-ring and made sure that it was properly seated, I have not had a problem since. You might want to check this area also as from what I read, your mechanic had taken the engine fuel filter off.

Regards

Ian Shepherd SM2K 414 Crusader -Cyprus

On 14/06/2020 05:48, Michael & Robyn wrote:

[Edited Message Follows]
[Reason: fixed Razor to RACOR]

Update on Fuel issue.
We ran the engine for a total of 14 hours on our passage into the Chesapeake Bay and up north to Cambridge MD.
Three hours of these were at 2100 RPM.
NO further issues.

Thank you all for your helpful suggestions.

I have no proof but the most likely explanation is that the air was introduced when the mechanic took the RACOR filters out for visual inspection and put them back in stating that they are in excellent condition and do not need to be changed.
I assume our heavy rolling had pushed the air toward the engine.

To James point I have a suspicion that our fuel vacuum gauge may have failed too.
Given how little fuel our 100hp diesels consume and with a full tank I expect not much of a vacuum unless the filters would be really clogged badly.
I consider to replace the mechanical gauge with an electronic vacuum sensor and wire it up to an instrument at the engine control panel.
I still have to investigate why the sensor on the engine fuel filter doesn't show on the engine control panel.

Reading Kent's post I will definitely change the RACOR filters and the engine fuel filter.
My question now is how do you get the air out of the RACOR filters after changing the cartridge?
--
Michael & Robyn

SY RIPPLE SM2K # 417
now in Cambridge MD USA
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