Poulan 176038 - Manual (Page 23)

23
SERVICE AND ADJUSTMENTS
ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 29)
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 from
slow to choke position. Slowly move lever from choke
to fast position.
• Check that holes “A” in governor control lever and hole
in governor plate line-up. If holes “A” are not aligned,
loosen clamp screw and move throttle cable until holes
are aligned. Tighten clamp screw securely.
FIG. 29
FIG. 30
TO ADJUST CARBURETOR (See Fig. 30 )
NOTE: The carburetor on this engine is low emission. It is
equipped with an idle fuel adjusting needle with a limiter cap,
which allows some adjustment within the limits allowed by
the cap. Do not attempt to remove the limiter cap. The
limiter cap cannot be removed without breaking the adjust-
ing needle.
The carburetor has been preset 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 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 fuel/air mixture.
IMPORTANT: DAMAGE TO THE NEEDLE VALVE AND
THE SEAT IN CARBURETOR MAY RESULT IF 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).
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 idle mixture valve full travel clockwise then counter-
clockwise until engine runs rough. Turn valve to a point
midway between those two positions. Release throttle
lever.
ACCELERATION TEST -
•
Move throttle control lever from slow to fast position. If
engine hesitates or dies, turn idle mixture valve out
(counterclockwise) 1/8 turn. Repeat 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 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.
GOVERNOR
CONTROL LEVER
GOVERNOR
CONTROL
PLATE
CLAMP
SCREW HOLES "A"
THROTTLE
LEVER IDLE SPEED
SCREW
IDLE MIXTURE
VALVE WITH
LIMITER
THROTTLE
CABLE