1965 Evinrude SportFour Heavy Duty 60 HP Outboards Service Manual, 4204, Page 14Get this manual
DESCRIPTION FUEL FLOW The Sportfour 60 HP fuel system consists of fuel tank, fuel pump, and carburetorThe fuel tank is non-pressurized, suction operatedA diaphragmdisplacement type fuel pump on the motor draws fuel from the tank and furnispes it to the carburetor through fuel filter CARBURETOR The carburetor is two-barrel, downdraft typeSee Figure 3-1High- and low-speed needle valves are adjustableCarburetor and magneto are synchronized through an adjustable linkageLEAF VALVES There are four individual leaf block assemblies, one for each cylinder, but all attached to common leaf plate baseEach leaf block assembly has twin 4segment leaf valves attached, one on each sideThe entire assembly is mounted between the crankcase and intake manifold, and may be removed for inspection and repairsSee Figure 3-2CHOKE AND CHOKE SOLENOID The carburetor is fitted with manual choke to reduce the ratio of air to fuel for cold startsTwo Figure 3-2Leaf Valve Assembly choke valves, one in the air inlet of each barrel, are mounted to common choke shaftWhen the choke lever is pulled out, the valves are held in closed pOSition, restricting the flow of air to the carburetorA choke SOlenoid, mounted on the carburetorcloses the choke valves when the choke switch is depressedThe choke solenoid operates the choke valves through spring, allowing the choke to open partia lly as crankcase suction increasesSee Figure 3-3FUEL PUMP The fuel pump is of the diaphragm-displac ement type, and is operated by changes in crankcase pressureAlternate suction and pressure in the crankcase are transmitted to the pump diaphragm through flexible hoseSuction created on the upward stroke of the piston causes the diaphragm to displace and draw in fuel through the inlet valveOn the folCHOKE KNOB