Husqvarna LTH140 owner manual To Adjust Carburetor See Fig, Preliminary Setting, Final Setting

SERVICE AND 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 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 IN CARBURETOR MAY RESULT IF NEEDLE IS TURNED IN TOO TIGHT.

PRELIMINARY SETTING -

•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 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.

•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 fuel needle setting - With throttle control lever in slow ( ) 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.

•Recheck idle speed. Readjust if necessary.

ACCELERATION TEST -

•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 THINK THE ENGINE-GOVERNED HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR N E A R E S T A U T H O R I Z E D S E R V I C E C E N T E R / DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND E X P E R I E N C E T O M A K E A N Y N E C E S S A R Y ADJUSTMENTS.

IDLE SPEED

ADJUSTING

SCREW

IDLE FUEL

ADJUSTING

NEEDLE

FIG. 34

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