1997 Johnson Evinrude "EU" Accessories Service Manual, P/N 507270, Page 119Get this manual
Component Description
Trim-Up Relief ValveThis valve controls maximum oil pressure in the system during trim-outltilt-upIt also bleeds oil to the reservoir when the engine is run at speeds over 1500 RPM (approximately) in the partial-tilt positionThis allows the engine to return to the maximum trim-out position