Sears 917.251551 - Manual (Page 27)

TO ADJUST CARBURETOR (See Fig. 33)
The carburetor has been present at the factory and adjust­
ment should not be necessary. 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
fuel/air mixture. Turning the adjusting needles out (coun­
terclockwise) 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 SCREW IS
TURNED IN TOO TIGHT
PRELIMINARY SETTING -
• Be sure you have a clean air filter, and the throttle
control cable is adjusted properly (see ‘TO ADJUST
THROTTLE CONTROL CABLE" in the Service and
Adjustments section of this manual) .
• With engine off turn idle fuel adjusting needle in (clock­
wise) closing It finger tight and then turn out (counter­
clockwise) 1 turn.
FINAL SETTING -
0 start engine and allow to warm for five minutes. Make
final adjustments with engine running and shift/mollon
control lever in neutral (N) position.
» The high idle is set at the factory and cannot be
adjusted.
• Idle speed setting - With throttle control lever in slow
( • m ) position, engine should idle at 1200 RPM. If
engine idles too slow or fast, turn idle speed adjusting
screw in or out until correct idle is attained.
° Idle fuel needle setting - With throttle control lever in
slow (*•) position, turn idle fuel adjusting needle in
(clockwise) until engine speed decreases and then '
turn out (counterclockwise) approximately 3/4 turn to
obtain the best low speed performance.
» Recheck idle speed. Readjust if necessary.
ACCELERATION TEST -
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 IS FACTORY SET FOR PROPER
ENGINE SPEED, OVERSPEEDING THE ENGINE ABOVE
THE FACTORY HIGH SPEED SETTING CAN BE
DANGEROUS,' IF YOU THINKTHE ENGINE-GOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST AUTHORIZED SERVICE CENTER/
DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND
EXPERIENCE TO MAKE ANY NECESSARY '
ADJUSTMENTS
______ SE^VBCE AMD ADJUSTMENTS
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