Evinrude 4906B 4HP 1969 Owner's Manual page 34

Start the engine and allow it to warm to
operating temperature.
CAUTION: Water must circulate through
the lower unit to the engine any time the en-
gine is run to prevent
pump in the lower unit. Just five seconds
without water will damage the water pump.
NEVER, AGAIN NEVER, operate the en-
gine at high speed with a flush device at-
tached. The engine, operating at high speed
with such a device attached,
WAY from lack of a load on the propeller,
causing extensive damage.
With t he engine running in forward gear,
slow ly turn the idle mixture screw
TERCLOCKWISE until the affected
ders start to load up or fire unevenly, due to
an over-rich mixture.
mixture screw CLOCKWISE until the cylin-
ders fire evenly and engine rpm increases.
Continue to slowly turn the screw CLOCK-
WISE until too lean a mixture
and the rpms fall off and the engine begins
to misfire. Now, set the idle mixture screw
one-quarter 0/4) turn
wise) from the lean-out position.
justment will result in an approximate
setting. A too-lean setting is a major cause
of hard starting a cold engine.
to have the adjustment
rather than on the lean side.
another way, do not make the adjustment
A 3.0 hp engine with the low- and high-speed adjust-
m
ents clearly visible.
damage to the water
would RUN-A-
COUN-
cylin-
Slowly turn the idle
is obtained
out <Counterclock-
This ad-
true
It is better
on the rich side
Stating it
an y leaner than necessary to obtain a smooth
idle.
If the engine hesitates during acceleration
after adjusting the idle mixture, the mixture is
too lean. Enrich the mixture slightly, by turn-
ing the adjustment
engine accelerates correctly.
With the engine running in forward gear,
rotate the nylon idle adjustment screw, located
on the portside of the powerhead
powerhead idles at the recommended
This idle adjustment screw is always exposed on
the outside of the shroud.
Repairs and Adjustments
For detailed procedures
clean, assemble, and adjust the carburetor,
see the appropriate
the carburetor type on the engine being
serviced.
2-9 FUEL PUMPS
Many times a
defective
phragm is mistakenly
lem the ignition system.
in
mon problem is a tiny pin-hole in the dia-
phragm. Such a small hole will permit gas
A larger hp engine with the idle return
indicated. This stop screw is adjustable
the throttle from returning
engine.
FUEL PUMP
screw outward until the
until the
rpm.
to disassemble,
section in Chapter 4 for
fuel pump dia-
diagnosed as a prob-
The most com-
stop screw
and prevents
so as to
far shut down the
2-9