Carburetor; Carburetor Adjustments; Starting - Craftsman weedwacker 358.798420 Operator's Manual

SERVICE AND ADJUSTMENTS
MIXTURE SCREW (WITH LIMNER CAP)
Carburetor adjustment is critical and If done Improper-
ly can permanently damage the engine as well as the
carburetor. Please read all Instructions and consult the
Troubleshooting sactlon of this manual before begin-
nlng this process. If the engine does not operate
according to these instructions after repeating the
adjusting steps, do not use the unit. For further assls-
tence, please call our customer assistance hotline at
1-800-235-5878.
WARNING:
MAKE CARBURETOR ADJUSTMENTS WITH
THE LOWER END SUPPORTED TO PREVENT
SEMI-AUTOMATIC HEAD FROM CONTACTING
ANY OBJECT. HOLD UNIT WITH YOUR HAND. ;
THE SEMI-AUTOMATIC HEAD WILL BE SPIN-
NING DURING MOST OF THIS PROCEDURE.
WEAR YOUR PROTECTIVE EQUIPMENT AND
OBSERVE ALL SAFETY PRECAUTIONS.
IN MIXTURE ADJUSTMENT, RECHECK IDLE
SPEED AFTER EACH ADJUSTMEN_ THE
SEMFAUTOMATIC HEAD MUST NOTMOVEAT
IDLE SPEED.
engine does not start, it may be flooded. If in doubt read
the section on flooded engine in the starting section of this
manual prior to beginning any adjustments.
The carburetor has been adjusted at the factory for sea
level conditions. Adjustments may become necessary if the
unit is used at significantly higher altitudes or if you notice
any of the following conditions:
• Engine will not idle. See "Idle Speed Adjustment" and
"Mixture Speed Adjustment".
• Engine dies or hesitates when it should accelerate. See
"Acceleration Check".
• Loss of cutting power which is not corrected by air filter
cleaning. See =Mixture Speed Adjustment",
NOTE: There are two adjustments on the carburetor.
• The Idle Speed Adjustment.
• The Mixture Adjustment.
CARBURETOR PRESETS (Fig. 27)
If your engine will not start due to suspected improper c_r-
buretor adjustment, the following presets may be required.
If used, it is recommended that all steps withingthe adjust-
ment procedure be completed in order to assure a proper-
ly set carburetor. If presets are not needed, proceed to sec-
tion "Idle Speed Adjustment".
When making adjustments, be careful not to force the plas-
tic limiter caps beyond the stops or damage will occur.
Very small adjustments can affect engine performance. It is
important to make slight adjustments and test performance
before proceeding. Each adjustment should be no more
than 1/16th of a turn.
• Turn the mixture adjustment fully counterclockwiseto the
limiter cap stops.
• Turn idle speed adjustment clockwise one full turn.
• If engine fails to start after performingcarburetor presets,
the unit may be flooded. Review the =Difficult Starting"
section of the manual. If problems continue, call the 1-
800 number listed on the front cover of this manual for
further assistance.
• Start the engine and operate for three (3) minutes to
warm up. Go to =Adjusting Procedure".
COVER
IOLE SPEED SCREW
Figure 27
ADJUSTING PROCEDURE
IDLE SPEED ADJUSTMENT
• Allow the warm engine to idle.
• Adjust the Idle Speed until the engine continues to run
without stalling and without the semi-automatic head
turning.
- Turn screw clockwise to increase engine speed if
engine stalls or dies.
- Turn screw counterclockwise to slow engine down.
• Follow instructions in "Acceleration Check'.
• No further adjustments are necessary if performance is
satisfactory.
MIXTURE ADJUSTMENT
• Support the lower end so the semi-automatic head is
off the ground and will not make contact with any object.
Be sure the trimmer line is extended to the maximum
length allowed by the line limiter.
* Start the engine. Allow engine to idle, then squeeze
throttle trigger fully.
NOTE: Perform steps below at full throttle.
• Turn mixture screw counterclockwise to the limiter cap
stop.
• Run engine at full throttle for 30 seconds.
• If engine is running rough, turn mixture screw clockwise
in 1/16th turn increments until engine just starts to run
smoothly.
• Do not attempt to adjust screw beyond stops as damage
will occur.
• After completing adjustments, check for acceleration.
• If the unit accelerates and runs smoothly, no further
adjustments are necessary. If not, proceed to
"Acceleration Check".
ACCELERATION CHECK
• Allow engine to idle.
• Squeeze trigger fully.
- If performance is satisfactory (engine accelerates
smoothly), no further adjustments are necessary.
- If the engine does not accelerate smoothly, turn the
mixture screw counterclockwise a small amount (no
more than the width of the slot in the adjusting screw).
• Repeat step above until smoothacceleration is obtained.
Do not attempt to adjust the screw beyond the stop as
damage will occur.
NOTE: It may be necessary to repeat =Idle speed
Adjustment"through "AccelerationCheck,"to obtain correct
adjustments.
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