Throttle Control; Choke Control; Spark Control - Chevrolet Fleetmaster Series 1947 Owner's Manual

Fig. 6-Throttle Knob
THROTTLE CONTROL
The opening and closing of the
throttle valve in the carburetor is
controlled from the driving compart-
ment by the accelerator pedal, but it
is sometimes advisable to use the
throttle knob on the instrument
panel. Pulling out the throttle knob
will open the throttle.
CHOKE CONTROL
When starting a cold engine, it is necessary to provide a fuel ·
mixture richer in gasoline than is ordinarily required.
The correct use of the choke is
extremely important; if improperly
handled it may seriously affect the life
of the engine by the thinning effect
on the lubricating oil of unburned
gasoline leaking by the pistons.
The choke should not be used if
the engine retains any heat from pre-
vious running, without first attempt-
ing to start the engine with its normal
fuel mixture.
If the choke has been used exces-
Fig. 7-Choke Knob
sively, causing failure to start, open the throttle to admit sufficient
air to overcome the overloaded condition of the engine.
SPARK CONTROL
The spark timirlg of the Chevrolet engine is controlled by two
engineering features: 1 .,. .'
11
Th 0 t . S i t
. "r"anuq
y'- . e cane e eC or
-For maximum economy and per-
formance the octane selector must be
advanced as far as possible without
causing the engine to knock at wide
open throttle. When the lower octane
(lower grade) fuels are used, the selec-
tor should be retarded. Higher octane
fuels permit more advance, resulting
in a still greater economy and better
Fig. 8-0ctane Selector
performance.
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