Replace Spark Plug - Craftsman 358.798940 Operator's Manual

REPLACE SPARK PLUG
Replace spark plug each year to en-
surethe engine starts easier and runs
better. Set spark plug gap at .025 in.
Ignition timing is fixed, nonadjustable.
° Twist, then pull off spark plug boot.
= Remove spark plug from cylinder and
discard.
• Replace with Champion RCJ-SY
spark plug and tighten with a 3/4 in.
socket wrench (10-12 ff.-Ibs).
• Reinstall the spark plug boot.
We recommend all service and adjust-
ments not listed in this manual be per-
formed by your Sears Service Center°
CARBURETOR ADJUSTMENT
Carburetor adjustment is critical and if
done improperly can permanently dam-
age the engine as well as the carbure-
tor_ If you require further assistance or
are unsure about performing this pro-
cedure, call our customer assistance
help line at 1-800-235-5878.
Old fuel, a dirty air filter; a dirty fuel fil-
ter; or flooding may give the impression
of an improperly adjusted carburetor.
Check these conditions before adjust-
ing the carburetor.
The carburetor has been carefully set
at the factory° Adjustments may be
necessary if you notice any of the fol-
lowing conditions:
. Engine will not idleo See "Idle Speed"
and "Mixture" under adjusting
procedure.
o Engine dies or hesitates instead of
accelerating. See "Acceleration
Check" under adjusting procedure,,
• Loss of power. See "Mixture" under
adjusting procedure.
There are two adjustment screws on
the carburetor. They are located in the
area below the throttle/choke knob.
Mixture Screw with Limiter Cap
CARBURETOR PRESETS
When making carburetor preset adjust-
ments, do not force plastic limiter caps
beyond the stops or damage will occur.
If carburetor presets are not needed,
proceed to "ADJUSTING PROCEDURE,
Idle Speed."
To adjust presets:
° Turn the mixture screw counterclock-
wise until it stops°
• Turn the idle speed screw clockwise
until it stops. Now turn counterclock-
wise 4-1/2 turns°
Start motor, let it run for 3 minutes, and
proceed to the adjustment section, tf
engine does not start, refer to trouble-
shooting chart or call 1-800-235-5878.
If engine performance is acceptable at
the preset positions, no further adjust-
ments are necessary_
ADJUSTING PROCEDURE
idle Speed
Allow engine to idle. Adjust speed until
engine runs without stalling.
° Turn clockwise to increase engine
speed if engine stalls or dies.
• Turn counterclockwise to decrease
speed.
No further adjustments are necessar t if
performance is satisfactory.
Mixture
Allow engine to idler Then accelerate
the engine and note performance, tf
engine hesitates, bogs down, or
smokes during acceleration, turn mix-
ture screw clockwise in !/16-turn incre-
ments until performance is satisfactory.
Repeat this procedure as necessary
for proper adjustment. After completing
adjustments, check for acceleration.
Reset if necessary.
Acceleration Check
If engine dies or hesitates instead of
accelerating, turn low speed mixture
adjustment counterclockwise until you
have smooth acceleration_ Recheck
and adjust as necessary for acceptable
performance_
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