Evinrude 4906B 4HP 1969, Owner'S Manual

Page: 97 / 422

4-6 FUEL
If the choke should stick in the open
position, the engine will be hard to start. If
the choke should stick in the closed position,
the engine will flood making
it
VERY diffi-
cult to start.
In order for this raw fuel to vaporize
enough to burn, considerable air must be
added to lean out the mixture. Therefore,
the only remedy is to remove the spark
plug/s; ground the leads; crank the engine
through about 10 revolutions; clean the
plugs; install the plugs again; and start the
engine.
If the needle valve and seat assembly is
leaking, an excessive amount of fuel may
enter the intake manifold in the following
manner: After the engine is shut down, the
pressure left in the fuel line will force fuel
past the leaking needle valve. This extra
fuel will raise the level in the fuel bowl and
cause fuel to overflow into the intake mani-
fold.
A continuous overflow of fuel into the
intake manifold may be due to a sticking
inlet needle or to a defective float which
would cause an extra high level of fuel in
the bowl and overflow into the intake mani-
fold.
FUEL PUMP TESTS
CAUTION: Gasoline will be flowing in the
engine area during this test. Therefore, guard
against fire by grounding the high-tension
wire to prevent it from sparking.
CHOKE VALVE
The choke plays a most important role during engine
start and in controlling the amount
of air
entering the
carburetor, under various load conditions.
~
Grounding the spark plug 'wires during fuel tests
to
prevent an accidental spark
from
igniting fuel
or
fuel
vapors. Exercise care when working on the fuel system.
Testing System with Squeeze Bulb
An adequate safety method, is to ground
each spark plug lead. Disconnect the fuel
line at the carburetor. Place a suitable
container over the end of the fuel line to
catch the fuel discharged. Insert a small
screwdriver into the end of the line to open
the check valve, and then squeeze the prim-
er bulb and observe if there is satisfactory
fuel flow from the line.
The fuel line quick-disconnect fitting at the engine
separated
in
preparation
to
making
a
fuel
[lir»
test.