Evinrude 4906B 4HP 1969 Owner's Manual page 93

4-2 FUEL
Typical fuel line with
disconnect fitting at each end.
an
purchased as assembled unit.
On models produced from
1959, the fuel tank is equipped with a hand
pressure pump. Operation
forces fuel to the carburetor
After engine start,
cylinder is fed through a hose to the tank.
Therefore, the pressurized
tains a steady
fuel
while the engine is operating.
necessary because the
have sufficient pressure to draw fuel from
the tank during cranking before the engine
starts.
Since 1960, most
ped with a manually-operated
in the line to transfer
the engine until the engine starts.
After the engine starts,
through the fuel pump to the carburetor.
All systems have some type of filter install-
ed somewhere in the
and the carburetor,
pressure fuel tank systems.
sure fuel tank arrangement,
actually an intergral part of the fuel pickup
Obsolete pressure-type
1958.
until about The system
squeeze bulb arrangement
page.
squeeze bulb and quick-
These items may
1956 through
of this pump
for starting.
the pressure from one
fuel tank main-
supply to the engine
This action is
pump does not
fuel
systems are equip-
fuel
squeeze bulb
fuel from the tank to
the fuel passes
line between the tank
except the old-style
With the pres-
the filter
fuel tank used extensively
was replaced by the
at
shown the top of this
be
Two different
removed to show the filter
be
rebuilt. The only
screens with solvent and then blow them dry.
in the tank.
integral part of the carburetor.
At the
through the inlet passage to the needle and
seat, and then into the float chamber (reser-
voir). A float in the chamber rides up and
down on the surface of the fuel.
enters the chamber and the level rises to a
predetermined
closes the inlet
entering the chamber is cutoff.
leaves the chamber as the engine operates,
the fuel level
allows the inlet needle to move off its seat
and fuel once again enters the chamber.
this manner a constant
maintained
demands of the engine at all speeds.
is
Fuel pump installed
may be rebuilt,
type fuel pumps with
screen. These pumps cannot
service
possible
Many units have a filter as an
carburetor, the fuel
point, a tang on the float
needle and the
drops and the float
reservoir
in the chamber to satisfy
on the engine. This type pump
as explained in the text.
the covers
to
is clean the
passes
After fuel
flow of
When fuel
tang
In
of fuel is
the