To Adjust Choke Control; To Adjust Carburetor; Acceleration Test - Craftsman 917.270780 Owner's Manual

19.0 hp electric start 42" mower automatic lawn tractor
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TO ADJUSTCHOKECONTROL
The chokecontrolhas beenpreset
at the
factory and adjustment should not be nec-
essary.
Check adjustment as described
below before loosening cable.
If adjust-
ment is necessary, proceed as follows:
• With engine not running, move choke
control (located on dash panel) to full
choke position.
• Remove air cleaner cover, filter and car-
tridge plate to expose carburetor choke
(see "AIR FILTER" in the Customer
Responsibilities section of this manual).
• Choke should be closed. If it is not,
loosen casing clamp screw and move
choke cable until choke is completely
closed. Tighten casing clamp screw se-
curely.
• Reassemble
air cleaner.
Clamp
Quarter Cimle
Casing
Choke
Clamp
Lever
TO ADJUSTCARBURETOR
The carburetor has been preset at the fac-
tory and adjustment should not be neces-
sary. 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 mixture screw in
(clockwise) decreases_a're_J_pply of fuel to
the engine giving a leaner fuel/air
mixture.
Tuming the mixture screw 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 it screw
is turned in too tight.
PRELIMINARY
SE'I-I-ING
• Be sure you have a clean air filter, and
the throttle control cable and choke are
adjusted properly
(see above).
• With engine off turn idle mixture screw
in (clockwise) closing itfinger tight and
then tum out (countemlockwise) 1-1/4
to 1-112 turns.
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.
• With throttle control lever in slow posi-
tion, hold throttle lever against idle
speed screw and adjust idle speed
screw to obtain 1200 to 1400 RPM.
• While still holding throttle lever against
idle speed screw, turn idle mixture
screw in (clockwise) until engine begins
to die and then turn out (counterclock-
wise) until engine runs rough. Tum
screw to a point midway between those
two positions.
• Continue to hold throttle lever against
idle speed screw and adjust idle speed
screw to obtain 900 to 1200 RPM.
Re-
lease throttle lever.
ACCELERATION
TEST
• Move throttle control lever from slow to
fast position.
If engine hesitates or dies,
turn idle mixture screw out (counter-
clockwise) 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 the factory high speed set-
ting can be dangerous.
If you think the
engine-governed
high speed needs
adjusting,
contact your nearest authorized
service center/department,
which has
proper equipment and experience to make
any necessary adjustments.
Idle Speed
27
Throttle
Idle Mixture
Lever-...
ldle Speed
Screw
le Mixture
rew
Lever

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