Fuel Circulation Pump - Evinrude E-TEC 200 Service Manual

FUEL SYSTEM
COMPONENTS
Fuel Reservoir
The vapor separator accumulates fuel in an inter-
nal fuel reservoir and supplies fuel to the electric
circulation pump. It is water-cooled to enhance
vapor separating capabilities.
Cooling
Water is used to cool the fuel as it flows through
the vapor separator. The cooling passage of the
separator self-drains when the outboard is stored
vertically. Refer to HOSE ROUTING AND WATER
FLOW DIAGRAM on p. 184.
Venting
The fuel vapor vent regulates fuel vapor pressure
in the reservoir.
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1. Vent
1. Vent hose connection to intake
The vapor separator vent is opened and closed by
a float valve. The float valve moves relative to the
fuel level in the fuel chamber. Hot fuel causes an
increase in vapor pressure. This results in a lower
fuel level in the vapor separator. The float valve
drops and the vent opens. This allows fuel vapor
136
to flow to the intake manifold through the vent
hose.
As the vapor pressure in the vapor separator
decreases, the fuel level begins to increase. An
increase in the fuel level raises the float valve and
the vent closes.
Pressure Regulator
The fuel pressure regulator helps maintain consis-
tent fuel pressure in the fuel system.
Fuel returning from the injectors enters the fuel
chamber of the vapor separator through a pres-
sure regulator. The pressure regulator maintains
approximately 20 to 30 psi (138 to 207 kPa) of fuel
pressure in the high pressure side of the fuel sys-
tem.

Fuel Circulation Pump

The fuel circulation pump is an electric high pres-
sure fuel pump.
Fuel Supply
The pump is mounted to the vapor separator and
draws fuel from the fuel chamber. It pumps pres-
surized fuel through a fuel supply manifold con-
nected to the fuel injectors.
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Electrical Circuit
The circulation pump is controlled by the EMM
and operates on the 12 V circuit. The circulation
pump is activated momentarily when the EMM
1
powers up. The EMM controls pump operation by
rapidly connecting and disconnecting the pump's
internal coil to ground.
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