To Adjust Throttle Control Cable; To Adjust Carburetor; Acceleration Test; Preliminary Setting - Craftsman 917.255981 Owner's Manual

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SERVICE AN ADJUSTMENTS
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E N GIN E ACC ELERATION TEST-
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 38 & 39)
The throttle control has been preset at the factory and
adjustment should notbe necessary, Checkadjustment as
described below before loosening cable. If adjustment is
necessary, proceed as foilows:
° With engine not running, move throttle control leverto
fast 0 position°
° Check that speed control Iever is against stop screw. If
it is not, loosen casing clamp screw and pull throttle
cable until lever is against screw_ Tighten clamp screw
securely.
TO ADJUST CARBURETOR (See Fig. 40)
The carburetor has been present at the factory and adjust-
merit should not be necessary. However, minor adjustment
may be required to compensate for differences in fuel,
temperature, altitude or load. If the carburetor does not
need adjustment, proceed as follows:
In general, turning the adjusting needles in (clockwise)
decreases the supply of fuel to the engine giving a leaner
fuel/air mixture_ Turning the adjusting needles out (coun-
terclockwise) increases the supply of fuel to the engine
giving a richer fueVair mixture.
IMPORTANT: DAMAGE TO THE NEEDLES AND THE
SEATS IN CARBURETOR MAY RESULT IF SCREW IS
TURNED _NTOO TIGHT_
,, Move throttle control lever from slow 0 to fast 0
position. If engine hesitates or dies, turn idle mixture
screw out (counterclockwise) t/8 turn. Repeattestand
continue to adjust, if necessary, until engine acceler-
ates 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 SETTING CAN BE
DANGEROUS. IF YOU THINK THE ENGINE-GOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST AUTHORIZED SERVICE CENTER/
DEPARTMENT, WHICH HAS PROPER EQUIPMENTAND
EXPERIENCE TO MAKE ANY NECESSARY
ADJUSTMENTS.
PRELIMINARY SETTING -
= Be sure you have a clean air filter, and the throttle
control cabie is adjusted properly (see above).
o With engine off turn idle fuel adjusting needle in (cfock-
wise) c[ostng it finger tight and then turn out (counter-
clockwise) 1-1/4 turns°
- Turn main fuel adjusting needle in (clockwise) closing
linger tight and then turn out (counte rclockwise) 1 turn.
FINAL SETTING -
= Start engine and allow to warm for five minutes., Make
final adjustments with engine running and shift/motion
control lever in neutral (N) position.
= With throttle control lever in fast 0 position, turn main
fuel adjusting needle in (clockwise) until engine begins
to die then turn out (cotJnterclockwise) until engine
runs rough. Turn needle to a point midway between
those two positions.
,, !dle speed setting - With throttle control lever in slow 0
position, engine should idle at 1400 RPM If engine
idies too slow or fast, turn idle speed adjusting screw in
or out until correct idle is attained
o !die fuel needle setting - With throttle contro_ lever in
slow () position, turn idle fuel adjusting needle in
(clockwise) unti_ 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. Readiust if necessary
CASING STOP SCREW SPEED CONTROL
CLAMP LEVER
THROTTLE
CONTROL
CABLE
FIG. 38
STOP
SCREW
SPEED
CONTROL
LEVER
FIG. 39
IDLE FUEL
ADJUSTING
EEDLE
25 FIG. 40