Low oil pressure at idle only Yanmar 4JHE

[jimbunyard]

In my experience there is no 'normal' in the placement of oil pressure taps beyond them being in or near a main oil passage.

For this engine, according to the exploded views found here,

https://www.yanmarshop.com/catalogue...he-series-4jhe

there are three possible places, two at the aft end of the main gallery as shown in the first drawing above, the 'A' position and the normally plugged one just forward of it.

There is also a tap in the oil filter housing on the forward end in the middle of the engine on the starboard (with a conventionally mounted engine) side.

The oil pump is on the front of the engine, driven by the crank gear.

As before, my opinion is that there is nothing to worry about...a good feel can be had by taking the oil filler cap off and having a look inside. If the top of the engine is good and oily, chances are everything's good. If it's kind a dry looking, I'd be trying to find out why...