1972 Johnson 4HP Outboard Motor Service Manual, Page 23Get this manual
assure that the fuel tank contains the proper mixture, drain and flush the tank at least once year, and at every tune-up or major repairClean the tank flushing with clear gasoline or solventPrimer, screen, etc inspected and cleaned as described belowRefi1l the tank with the correct fuel mixtureDESCRIPTION The fuel tank is of simple but rugged construction, with capacity of gallons of fuel mixtureIt tains the bulb primer (for priming the fuelfuel hose and connector, bracket arrangement to hold fuel line when not in use, carry grip, and disc valve which prevents any escape of gasoline or fumes, minimizing the danger of explosion or fireSee Figure 3-18 from escapingcheck operation of the valve, alternately blow into the valve and draw outAir should but not escapeValve components can serviced unscrewing from tankSee Figure 3-20SEAT
Figure 3-20
Fuel Tank Vent Assembly
HOSE AND PRIMER BULB ASSEMBLY CLAMPS disassemble hose clamps, grip clamp with pliersBend overlapping hook backward (in direction of arrow) to release clampSee Figure 3-21assemble hose clamps, grip clamp firmly with pliersApply slight pressure to hook topside with screwdriverSqueeze clamp with pliers until hooks interlockSee Figure 3-22