Carburetor Adjustments; Carburetor Presets - Craftsman 358.797961-22cc Operator's Manual

SERVICE AND ADJUSTMENTS
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CARBURETOR ADJUSTMENTS
Carburetor adjustment is critical and if done improp-
erly can permanently damage the engine as well as
the carburetor. Please read all instructions and con-
sult the Troubleshooting section of this manual
before beginning this process.
• tf engine does not start, it may be flooded, if in doubt,
read the section on flooded engine in the starting section
of this manual priorto beginning any adjustments.
• Poor engine performance can be a result of other
causes such as dirty air filter, clogged muffler outlets,
dirty spark arrestor screen, etc, See the 'TROUBLE
SHOOTING CHART" before proceeding with carbure-
tor adjustments.
• If you are unsure about adjusting the carburetor or
experience any problem while attempting this process,
please call the 1-800 number listed on the front cover
of this manual for further assistance.
NOTE: Be sure to properly prepare the unit as described
in the "PREPARATION" section below.
The carburetor has been adjusted at the factory for
sea level conditions. Adjustments may become neces-
sary if the unit is used at significantly higher altitude or
if you notice any of the following conditions:
-Engine will not continue to run at idle position. See
"IDLE SPEED ADJUSTMENT" and "MIXTURE
ADJUSTMENT."
-Engine dies Or hesitates when it should accelerate.
See "ACCELERATION CHECK."
- Loss of power which cannot be corrected by clean-
ing air filter. See "MIXTURE ADJUSTMENT."
-Engine will not run. See 'TROUBLE SHOOTING
CHART." Then, if carburetor requires adjustment,
begin with "CARBURETOR PRESETS."
NOTE: Do not attempt to adjust the mixture screw
beyond the stops as damage can occur.
wARNING
THE IMPELLER WILL BE SPINNING DUR-
ING THIS PROCEDURE. WEAR YOUR
PROTECTIVE EQUIPMENT AND
OBSERVE ALL SAFETY INSTRUCTIONS.
KEEP OTHERS AWAY WHEN MAKING
CARBURETOR ADJUSTMENTS.
THE MIXTURE SETTING IS A HIGHLY
CRITICAL ADJUSTMENT. IF SET INCOR-
RECTLY, PERMANENT DAMAGE WILL
OCCUR TO THE ENGINE. DO NOT RUN
ENGINE AT FULL THROTTLE FOR PRO-
LONGED PERIODS WHILE MAKING THE
MIXTURE ADJUSTMENT.
PREPARATION
Tools Required: Small standard screwdriver
• Stop the engine. Make sure your unit is fully assem-
bled with the tubes and nozzle in place.
• Use a fresh fuel mixture with proper gasoline/oil ration
(see Fueling Your Engine section).
• Place the uniton a solid, flat surface free of any loose
-debris.
• Locate the two carburetor adjusting screws. Fig. 15.
• Start the engine and operate for three (3) minutes to
warm up. The engine must be warm for proper adjust-
ments to be made.
• Go to"ADJUSTMENT PROCEDURE."
NOTE; If your unit will not start, proceed to section
"CARBURETOR PRESETS."
CARBURETOR PRESETS (Fig,15)
tf your engine will not start due to suspected improper
carburetor adjustment, the following presets may be
required. If used, it is recommended that all steps within
the adjustment procedure be completed in order to
assure a properly set carburetor. If presets are not need-
ed, proceed to section "IDLE SPEED ADJUSTMENT."
Very small adjustments can affect engine performance.
tt is important to turn the screw a very small amount per
adjustment and test performance before making further
adjustments. Each adjustment should be no more than
the width of the slot in the adjusting screw.
• Turn the mixture screw counterclockwise until it stops.
Do not attempt to adjust the screw beyond the stops
as damage can occur.
• Turn idle speed screw clockwise I/2 turn.
• Start the engine and operate for three (3) minutes to
warm up. Go to "ADJUSTING PROCEDURE."
Figure 15
-15-