To Adjust Carburetor; Acceleration Test - Craftsman 917.271080 Owner's Manual

TO ADJUST CARBURETOR
The carburetor has been preset at the fac-
tory and adjustment should not be neces-
sary. However, minor adjustment may be
required to compensate for differences in
fuel, temperature, altitude or load. If the
carburetor does need adjustment, proceed
as follows:
In general, turning the adjusting needles
in (clockwise) decreases the supply of fuel
to the engine giving a leaner fueVair mix-
ture. Turning the adjusting needles out
(counterclockwise) increases the supply of
fuel to the engine giving a richer fuel/air
mixture.
IMPORTANT: Damage to the needles and
the seats in carburetor may result if nee-
dle is turned in too tight.
NOTE: The carburetor on this engine is
low emission. It is equipped with an idle
fuel adjusting needle with a limiter cap,
which allows some adjustment within the
limits allowed by the cap. Do not attempt
to remove the limiter cap. The limiter cap
cannot be removed without breaking the
adjusting needle.
• Be sure you have a clean air filter and
the throttle control cable is adjusted
properly (see above).
• Start engine and allow to warm for five
minutes. Make adjustments with engine
running and shift]motion control lever in
neutral (N) position.
• Idle soeed settina - With throttle control
lever in slow position, engine should
idle at 1750 RPM. If engine idles too
slow or fast, turn idle speed adjusting
screw in or out until correct idle is at-
tained.
• Idle fuel needle settina - With throttle
control lever in slow position, turn idle
fuel adjustment needle in (clockwise)
until engine begins to die and then turn
out (counterclockwise) until engine runs
rough. Turn needle to a point midway
between those two positions.
• Recheck idle speed. Readjust if neces-
sary.
ACCELERATION TEST -
• Move throttle control lever from slow to
fast position. If engine hesitates or dies,
turn idle fuel adjusting needle out
(counterclockwise) 1/8 turn. Repeat test
and continue to adjust, if necessary,
until engine accelerates smoothly.
High speed stop is factory adjusted. Do
not adjust - damage may result.
IMPORTANT: Never tamper with the
engine governor, which is factory set for
proper engine speed. Overspeeding the
engine above the factory high speed set-
ting can be dangerous. If you think the
engine-governed high speed needs
adjusting, contact your nearest AUTHO-
RIZED service center/department, which
has proper equipment and experience to
make any necessary adjustments.
Screw
Speed Control
Bracket
Idle Speed
Adjusting
Screw
Throttle Lever
Idle Fuel
Adjusting
Needle
27