To Adjust Throttle Control Cable; Preliminary/Final Setting; Acceleration Test; Carburetor Adjustment - Craftsman 917.255430 Owner's Manual

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SERVICE ADJUSTMENTS
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ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 28)
The throttle control has been preset at the factory and
adjustment should not be necessary° Check adjustment as
described below before loosening cable.. If adjustment is
necessary, proceed as follows:
° With engine not running, move throttle control lever
from "SLOW"to "CHOKE" position° Slowly move lever
from "CHOKE" to "FAST" position.
* Checkthat holes"A" in governorcontro! lever and hole
in governor plate line-up. If holes "A" are not aligned,
loosen clamp screw and move throttle cable until holes
are aligned. Tighten clamp screw securely,
GOVERNOR
CONTROL LEVER
GOVERNOR
CONTROL PLATE
HOLES "A" CLAMP
SCREW
THROTi'LE
CABLE
FIG. 28
TO ADJUST CARBURETOR (See Fig. 29)
The carburetor has been preset at the factory and adjust-
ment should not be necessary. However, minor adjust-
ment may be required to compensate fordifferences in fuel,
temperature, altitude or load. if the carburetor does need
adjustment, proceed as follows:
In general, turnig idle mixture valve in (clockwise) de-
creasesthe supply of fuel tothe engine giving a leaner fueV
air mixture. Turning the idle mixture valve out (counter-
clockwise) increases the supply of fuel to the engine giving
a richer fuel/air mixture.
IMPORTANT: DAMAGE TO THE NEEDLE VALVE AND
-THE SEAT IN CARBURETOR MAY RESULT IF SCREW IS
TURNED IN TOO TIGHT.
PRELIMINARY SETTING -
• Air cleaner assembly must be assembled to the carbu-
retor when making carburetor adjustments.
= Be sure the throttle control cable is adjusted properly
(see above).
° With engine off turn idle mixture valve in (clockwise)
closing it finger tight and then turn out (counterclock-
wise) 1 full turn.
FINAL SETTING -
• Start engine and allowto warm forfive minutes. Make
final adjustments with engine running and shift/motion
control lever in NEUTRAL position.
• Move throttle control lever to "SLOW" position. With
finger, rotate and hold throttle lever against idle speed
screw. Tum idle speed screw to attain 1750 RPM.
• While still holding throttle lever against idle speed
screw, turn idle mixture valve in (clockwise) untlt en-
gine begins to die and then tu rn out (counterclockwise)
until engine runs rough. Turn valve to a point midway
between those two positions. Release throttle lever.
ACCELERATION TEST -
° Move throttle control lever from "SLOW" to "FAST"
position. If engine hesitates or dies, turn idle mixture
valve out (counterclockwise) 1/8 turn. Rep.eat test and
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. OVERSPEED1NG TH E ENGINE ABOVE
THE FACTORY HIGH SPEED SETTING CAN BE
DANGEROUS. IF YOU THINK THE ENGINE-GOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEARESTAUTHORIZED SERVICE CENTER, WHICH HAS
PROPER EQUIPMENTAND EXPERIENCE TO MAKE ANY
NECESSARY ADJUSTMENTS.,
THROTTLE IDLE SPEED
LEVER SCREW
IDLE MIXTURE
VALVE
FIG. 29
23