Craftsman 917.255560 Owner's Manual page 23

SERVICE AND ADJUST ENTS
ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 29)
The throttle control has been preset at the factory and
adjustment shoutd notbe necessary. Check adjustment as
described below before loosening cable, if adjustment is
necessary, proceed as fof6ows:
• With engine,,no!, running_, move throttle control lever
from SLOW to CHOKE position. SIowly movelever
from "CHOKE" to "FAST" position.
• Check that holes "A" in governor control 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
THROTTLE
CABLE
FIGo 29
TO ADJUST CARBURETOR (See Fig. 30)
The carburetor has been preset at the factory and adjust-
ment should not be necessary. However, minor adjust-
ment may be required to compensate for d{fferences in fuel,
temperature, aititude or load. if the carburetor does need
adjustment, proceed as follows:
In general, turnig idle mixture valve In (clockwise) de-
creases the supply of fuel to the engine giving a leaner fuel/
air mixture. Turning the idle mixture valve out (counter-
clockwise) increases the supply of fue_to the engine giving
a richer fuel/air mixture.
iMPORTANT: DAMAGE TO THE NEEDLE VALVE AND
THE SEAT tN CARBURETOR MAY RESULT iF SCREW kS
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 engir_ off turn idle mixture valve in (clockwise)
closing it fi_:ger tight and then turn out (counterclock-
wise) t fut_ 'i;_mo
FINAL SETTING -
• Start engine and allow to warm for five 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. Turn idle speed screw to attain 1750 RPM.
= While still holding throttle lever against idle speed
screw, turn idle mixture valve in (clockwise) until en-
gine begins to die and then turn out (counterclockwise)
until engine runs rough. Turn valve to a point midway
between those two positions. Release throttle tever.
ACCELERATION TEST -
° Move throttle control lever from "SLOW" to "FAST"
position. If engine hesitates or dies, turn idle mixture
valveout (counterclockwise) 1/8turn. Rep.eattest and
continue to adjust, if necessary, until eng=ne accelero
ates smoothly.
High speed stop is factory adjusted. Do not adjust o
damage may result.
iMPORTANT: NEVER TAMPER WtTH 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 THINKTHE ENGINE-GOVERNE_
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEARESTAUTHORIZED SERVICE CENTER, WHICH HAS
PROPER EQUIPMENT AND EXPERIENCE TO MAKE ANY
NECESSARY ADJUSTMENTS,
THROTTLE iDLE SPEED
LEVER SCREW
IDLE MIXTURE
VALVE
FIG. 30
23