1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 301Get this manual
Component Description Tilt Up Relief ValveThis valve controls maximum oil pressure during the tilt-up mode and provides pressure relief when the tilt cylinder is fully extendedIt 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 positionTilt Cylinder Relief ValveThis valve works in conjunction with the Tilt Up Relief Valve to accomplish the same task as the Tilt Up Relief ValveManual Release ValveThis device allows manual tilting movement of the engineWhen this valve is opened, the engine will not move in the trim rangeTilt CylinderThis hydraulic cylinder moves the engine through the entire tilt rangeI addition, this cylinder also acts as trim cylinder for the first 46mm (1-1316") (approximately), of its movement upwardTrim CylinderThis hydraulic cylinder works together with the tilt cylinder for the first 46mm (1-1316") of upward movementThe trim cylinder holds its position and provides positive hold for the engineThe trim cylinder also contains "bobbin" which measures the degree of trim at any given pointSending UnitThe sending unit, located on the trim cylinder, sends the signal from the "bobbin" to the trim indicator gauge and provides means of determining the angle of the engine