Craftsman 917.270742 Owner's Manual page 28

TO ADJUST CARBURETOR
NOTE: The carburetor on this engine is
!ow 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 adjusting needle.
The carburetor has been preset at the
factory and adjustment 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) decreases the supply of fuel
to the engine giving a leaner fuel!air
mixture. Turning the idle mixture valve
out (counterclockwise) increases the
supply of fuel to the engine giving a
richer fuel/air mixture,
IMPORTANT: Damage to the needle
valve and the seatin carburetor may
result if screw is turned in too tight.
PRELIMINARY SETTING -
• Air cleaner assembly must be as-
sembled to the carburetor when
making carburetor adjustments.
,, Be sure the throttle control cable is
adjusted properly (see above).
FINAL SETTING -
a 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
I750 RPM.
o While still holding throttle lever
against idle speed screw, turn idle
mixture valve full travel clockwise then
counterclockwise until engine runs
rough. Turn valve to a point midway
between those two positions. Re-
lease throttle lever.
ACCELERATION TEST -
o 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 neces-
sary, 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 nearest autho-
rized service center/department, which
has proper equipment and experience to
make any necessary adjustments.
Idle Speed Screw
Lever
Idle Mixture Valve ---'--_
with Limiter
28