2007 Evinrude E-Tec 75, 90 HP outboards Service Manual, Page 183Get this manual
OILING SYSTEM COMPONENTS
Oil Recirculation System
External hoses and fittings, internal cylindercrankcase passages, and intake manifold passages are used to "recirculate" any accumulation of oil from various locations in the powerheadThe movement of oil in these "oil circuits" is controlled by check valves
Cylinder Recirculation
Internal powerhead oil drain passages connect the intake port areas of the cylinders to circulate residual oil in the blockExternal fittings and in-line check valves on each side of the cylinder block control the movement of oil from the lower cylinder port to the upper cylinder port
Lower to upper main bearing oil flow: Lower main bearing cavity to internal crankcase passage to external fitting, external hoses with in-line check valve to external fitting at upper main bearing, and into upper main bearing through internal crankcase passage Internal crankcase passage to external fitting in crankcase cover at upper main bearing, hose routed to reed plate fittingThis circuit vents the upper main bearing cavity to promote oil flow