Sears 917.25271 sc. w, Service And, Adjustments, TO ADJUST THROTTLE CONTROL CABLE See, Engine

Models: 917.25271

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SERVICE AND

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SERVICE AND

ENGINE

TO ADJUST THROTTLE CONTROL CABLE

(See Fig. 33 & 34)

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 to fast (,#_) position.

Check that speed control lever 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. 35)

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 -

ADJUSTMENTS

ACCELERATION TEST -

°Move throttle control lever from slow (,_) to fast (,_) position. If engine hesitates or dies, turn idle mixture

screw out (counterclockwise) 1/8 turn. Repeat 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. 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.

CASING

STOPSCREW

SPEED CONTROL

CLAMP

 

LEVER

SCREW

 

 

THROTTLE

CABLE

Be sure you have a clean air filter, and the throttle control cable is adjusted properly (see above).

With engine off turn idle fuel adjusting needle in (clock- wise) closing it finger tight and then turn out (counter- clockwise) 1-1/4 turns.

FIG. 33

STOP

Turn main fuel adjusting needle in (clockwise) closing finger tight and then turn out (counterclockwise) 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 (,_) position, turn main fuel adjusting needle in (clockwise) until engine begins to die then turn out (counterclockwise) until engine runs rough. Turn needle to a point midway between those two positions.

Idle speed setting - With throttle control lever in slow (,=_) position, engine should idle at 1400 RPM. If

SPEED

CONTROL

LEVER

FIG. 34

IDLESPEED_.

_ _

/IDLE

FUEL

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

sc. w

 

slow (,g_) position, turn idle fuel adjusting needle in

 

(clockwise) until 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. Readjust if necessary.

26

FIG. 35

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Sears 917.25271 sc. w, Service And, Adjustments, TO ADJUST THROTTLE CONTROL CABLE See, TO ADJUST CARBURETOR See Fig