To Adjust Throttle Control Cable; To Adjust Carburetor; Preliminary Setting; Final Settin - Craftsman 917.257651 Owner's Manual

SERVmCE AND ADJUSTMENTS
ENGINE
ACCELERATION TEST-
TO
ADJUST THROTTLE
CONTROL CABLE
(See Fig. 31)
The throttle control has been preset at the factor*/ and
adjustment should not be necessary. Checkadjustment as
described below before loosening cabfe If adjustment is
necessary, proceed as follows:
, With engine not running, move throttle control lever
from slow (,.¢_.) to choke (\I) position Slowly move
lever from choke (1\1) to fast (,re,) post on
o Check to see if hole in throttle lever and hole in speed
control bracket are aligned
° If holes are not aligned, loosen cable clamp screw and
align the holes by inserting a pencil or a 1/4" drill bit
through both holes
o Pull throttle cable up to remove slack and tighten cable
clamp screw Remove alignment pencil or drill bit
TO ADJUST CARBURETOR (See Fig. 32)
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 tf 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
fuel/air mixture Turning the adjusting needles out (counter-
clockwise) increases the supply of fuel to the engine giving
a richer fuel/air mixture
IMPORTANT: DAMAGE TO THE NEEDLES AND THE
SEATS 1N CARBURETOR MAY RESULT tF NEEDLE IS
TURNED tN TOO TIGHT
PRELIMINARY SETTING -
• Be sure you have a dean air filter and the throttle
control cable is adiusted properly (see above)
• With engine off turn idle fuel adjusting needle in (clock-
wise) closing it finger tight and then turn out (counter-
clockwise) I turn
FINAL SETTING -
o Start engine and allow to warm for five minutes. Make
final adjustments with engine running and shift/motion
control lever in neutral (N) position
• Idle speed setting - 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 attained
• Idle f_el ne,_dle setting - With throttle control lever in
slow i-_._) position, turn idle fuel adjusting needle in
(clockwise) until engine begins to die and then turn out
(counterclockwise) approximately 1/8 to 1/4 turn to
obtain best low speed performance
o Recheck idle speed Readjust if necessary
o Move throttle control lever from slow (._) to fast (,_)
position If engine hesitates or dies, turn idle fuel
adjusting needle out (counterclockwise) 1/8 turn Re-
peat 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 tS FACTORY SET FOR PROPER
ENGINE SPEED OVERSPEEDING THE ENGINE ABOVE
THE FACTORY HIGH SPEED SETTING CAN BE
DANGEROUS IFYOUTHINKTHEENGINE-GOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST AUTHORIZED SERVICE CENTER/
DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND
EXPERIENCE TO MAKE ANY NECESSARY
ADJUSTMENTS
CABLE CLAMP SCREW_....._
SPEEDCONTROLBRACKET_
THROTTLE LEVER
FIG. 31
IDLE SPEED ADJUSTING SCREW
IDLE FUEL ADJUSTING NEEDLE
FIGo 32
23