1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 324Get this manual
Trouble Check Chart 1Cylinder leakdown Up check valve Manual release valve Impact relief valves Up relief valve Piston O-rings External leaks 2No reverse lock Filter valve and seat Impact relief valves Up relief valve Down check valve Piston O-rings External leaks 3No operation, motor runs Pump coupler Hydraulic pump Fluid level 4No tilt down Down relief valve Filter valve and seat Pump control piston Down check va Ive 5Slow performance Hydraulic pump Electric motor Mechanical binding Manual release valve Down relief valve Fluid level