1971 Johnson 4HP Outboard Motors Service Manual, Page 13Get this manual
TROUBLE 4POOR PERFORMANCE ON
CAUSE INCORRECT PROPELLER Incorrect tilt angle fueltoo much lubricant(smoking) hub slipping Bent worn Exhaust outlet damaged clogged Bent gear housing exhaust housing (broken driveshafts) Altitude horsepower Exhaust leaks Overheating ATION Protruding hull attachments too 10ng Bent (vibration) too high Improper 10ad distribution growth bottom Added weight (water absorption) Hook in bottom
SUBMERGED MOTORS
motor is 10st overboard while running, it should always disassembled before attempt is made to start itOften internal parts damaged, and attempts at starting runnil1g ul1der these conditions result in further damage
motor 10st overboard in salt water should always disassembled and cleaned before starting is attemptedSome materials used in modern engines are subject to very rapid corrosion in the presence of salt water and should inspected to determine if replacements requiredmotor 10st overboard in fresh water safely started if recovered wit hin twelve hours providing sand silt is present Remove the spark plu gs, he carburetor orifice screw, and drain fuel lines and tank the starter until water present has pelledSquirt outboard lubricant into spark plug holesReassemble and startIf sand has entered the el1gine,