M8 sumping...random thoughts on cause.

[Maddo Snr]

...I installed Harley's newly released oil pump cover 62400206 that has an large rubber seal that seals off the crank area from the cam chest and took it for a long high rpm ride. I made sure I shut it down without letting it idle and drained 1oz of oil. $25 fix

Could someone brighter than me please explain how SEALING OFF the location of the oil pooling (crankcase) from the point where the scavenge port picks up the sumped oil (camchest floor) can INCREASE the amount of oil scavenged?

At its simplest, this issue is the scavenge pump failing to evacuate the crankcase residual oil. Cutting off the oil flow to the scavenge side of the pump seems counter-intuitive.

I have some ideas that I want to check when I get my new M8 this week. My basic feeling is that the pressure differential between the oil tank void and the camchest void becomes greater than the scavenge pumps pressure generating capability, either that or there's some type of cavitation in the scavenge side of the pump.

I'm thinking the former. Old B motor Twinkies used a similar system for 10+ years with no issues. Can anyone shoot this theory down?