Oil pump pressure regulator

On my setup, these parts are NOT below the oil tank...

Tyler Stated:

On my setup, these parts are NOT below the Oil Tank...

The Installation manual instructs that the Oil Tank is to be installed such that the Normal Oil Level in the tank will be At or Above the center of the Oil Pump.

This assures that the Oil Pump will always retain its primed condition due to the effect of gravity acting on the Oil.

Are you saying that your Oil tank is located BELOW the level of the OILPump???

REF:  912 Installation manual, section 79-00-00, Chapter 2.3, Pages 18-19

Hmm, something is not adding up.  The way I read that section is that the maximum amount the normal oil level can be below the prop shaft is 15.75 inches.  I'm going to have to get out my tape measure tomorrow, but it seems to me (despite what the Fig 1. drawing suggests) that the center of the oil pump is a lot less than 15.75 inches below the prop shaft...

Digging more into the document (not being near my engine), according to 72-00-00, Figure 5 and Section 2.2, the distance from the center of the prop to the bottom of the engine is only 10.87 inches.  So, it seems to me that the "normal oil level" can actually be nearly 5" below the bottom of the engine proper and still be within spec...

My tank is definitely above the oil Pump so should be primed by gravity. I attached a photo

It's hard to tell from your photo, but it looks like your normal oil level is just about at the level of the prop shaft.  What's it's not ever supposed to be is any higher.

In any (every) case, the main worry when working on the system is not so much losing prime on the oil pump, but losing prime on the hydraulic valve tappets, which is much less obvious.  If in any doubt, there is a test for the latter, which involves pressing on the rocker arms: SI-04-1997 (r3), Section 3.1.3