Evinrude 4906B 4HP 1969 Owner's Manual page 101

4-10 FUEL
VENT
I
Sectional view of a
ing the filter inside the tank and the external
valve.
remedy is replacement.
modest and this one area is thus eliminated
as a problem source.
Would you believe,
fuel at the carburetor
vent on the fuel tank was not opened.
To remove the filter,
fuel tank filler cap, turn the engine upside
down and drain the tank.
the fuel line to the carburetor.
fuel shut-off valve.
will remain with the valve and can be separ-
ated from the valve by removing the fitting.
If the fitting and filter do not remain with
the valve when it is removed, then remove
the fi tting and filter from the tank.
CRACK
Cross-section view
principle parts with important
tory service.
FILTER
engine mounted fuel tank show-
shut-off
The cost is very
many times lack of
is caused because the
first remove the
Next, disconnect
Remove the
In most cases, the filter
INSULATOR
-:
SHELL
./
ADJUSTMENT
/
CENTER
ELECTRODE
of a spark plug showing
comments for satisfac-
of
A set points unfit for service
ROUGH ENGINE
If an engine does not idle smoothly, the
most reasonable
to perform
areas as:
plugs; and synchronization
ment.
Other problems that can prevent an en-
gine from running smoothly include:
leak in the intake
pression between
or broken reeds.
Of course any problem in the carburetor
affecting the air/fuel
vent the engine from operating
idle speed.
Too high a fuel level in the bowl; a heavy
float; leaking needle valve and seat; defec-
tive automatic
high-speed needle valve adjustments.
"Sour" fuel (fuel left in a tank without a
preservative
to run rough and
the
Inspection
whenever the engine failS
due to
IDLE
approach to the problem is
a tune-up to eliminate
defective points; faulty
out of adjust-
manifold; uneven com-
the cylinders;
mixture will also pre-
These problems usually include:
choke; and improper idle and
additive) will cause an engine
idle with great difficulty.
of
the spark plugs should become
to perform properly.
oxidation.
such
spark
An air
and sticky
smoothly at
a
"first"