Carburetor - Husqvarna GTH220 Owner's Manual

SERVICE AND ADJUSTMENTS
TO ADJUST CARBURETOR (See Fig. 37)
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 -
• Start engine and allow to warm for five minutes. Make
final adjustments with engine running and shift/motion
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
( ) 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 -
• Move throttle control lever from slow (
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
T H E F A C T O R Y H I G H S P E E D S E T T I N G C A N B E
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
DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND
E X P E R I E N C E T O
ADJUSTMENTS.
28
) to fast (
S E R V I C E C E N T E R /
M A K E A N Y N E C E S S A R Y
)