Sears 917.25953 owner manual Service A Adjustments, TO ADJUST CARBURETOR See Fig

SERVICE A ADJUSTMENTS

TO ADJUST CARBURETOR (See Fig. 34)

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 differences in fuel, temperature, altitude or load. If the carburetor does need adjustment, proceed as follows:

In general, turning 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 fuel to the engine giving a richer fue!/air mixture.

IMPORTANT: DAMAGE TO THE NEEDLE VALVE AND THE SEAT IN CARBURETOR MAY RESULT tF 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 vatve in (clockwise) closing it finger tight and then turn out (counterclock- wise) 1 full 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,

. 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 idte 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 lever,,

ACCELERATION TEST

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

vatveout (counterclockwise) 1/8turn. 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 WtTH THE ENGINE GOVERNOR, WHICH IS 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.

THROTTLE IDLE SPEED

LEVER_,____SCREW

IDLE MIXTURE

VALVE

FIG. 34

26