Carburetor Adjustments; Idle Speed Adjustment; Low Speed Mixture Adjustment; High Speed Mixture Adjustment - Craftsman 358.354870 Owner's Manual

Ea
CARBURETOR ADJUSlFIM N3'S
e The carburetor has been adjusted at the fac-
tory for sea level conditions, Adjustment may
become necessary if the unit is used at
significantly higher altitudes or if you notice
any of the following conditions:
--Chain moves with the engine at idle speed.
--Loss of cutting power which is not cor-
rected by air filter or muffler screen clean.
ingo
--Engine dies or hesitates when it should
accelerate.
e Permanent damage will occur to the engine if
incorrect carburetor adjustments are made./t
is best to let your Sears Service Center make
carburetor adjustments If you choose to
make the adjustment yourself, follow the pro-
cedure below very carefully.
WARNING!
The chain may be moving during this procedure.
Wear your protective gear and observe all of the
safety precautions.
.... i
1. PREPARATION
a. Stop engine
b. Use a fresh fuel mixture with proper
gasoline/oil ratio
c, Place the saw on a solid, flat surface and
make sure the chain will not contact any
object,.
d Locate the three (3) Carburetor adjusting
screws located on the fan housing side of
the saw. Figure 54
e. Turn the Low Speed Mixture Screw and the
High Speed Mixture Screw clockwise
just until they stop, Do not turn the screws
until they are tight as you may damage
the needle seats,
f, Turn the Low Speed Mixture Screw and the
High Speed Mixture Screw one full turn
counterclockwise
2. IDLE SPEED ADJUSTMENT--I
a. Start the engine and allow to idle.
b, Adjust if the engine dies or stops by turning
the Idle Speed Screw I/2 turn clockwise
NOTE: To increase idle speed, turn the Idle
Speed Screw clockwise _ To
decrease idle speed, turn the Idle Speed
Screw counterclockwise
c, Run the engine for a few minutes to bring it
up to operating temperature.
NOTE: The engine must be at operating
temperature for proper adjustments to be
made.
3o LOW SPEED MIXTURE ADJUSTMENT
a, Turn the Low Speed Mixture Screw slowly
clockwise _ until the RPM starts to
drop° Note the position,.
b Turn the Low Speed Mixture Screw coun-
terclockwise _ until th RPM speeds
up and starts to drop again, Note the posi-
tion.
c, Set the Low Speed Mixture Screw at the
mid-point between the two positions
4. IDLE SPEED ADJUSTMENT--II
a, Allow engine to idle.
b Adjust if the chain is turning by turning the
Idle Speed Screw counterclockwise _ o
c° Squeeze the throttle trigger; The saw
should accelerate without hesitating,
NOTE: It may be necessary to recheck the
low speed mixture setting after the idle
speed has been reduced by repeating "Low
Speed Mixture Adjustment" as in step 3
above,
5. HIGH SPEED MIXTURE ADJUSTMENT
a. Make a test cuL
b, Adjust if the saw smokes or seems to have
low power in the test cut by turning the
High Speed Mixture Screw 1t16th of a turn
clockwise
c. Repeat test cut,
d Repeat adjustment until the saw runs
smoothly..
[CAUTION: 1 Never set the High Speed Mixture
Screw less than 7/8 turn open, This is too lean
a setting and will ruin your engine.
.
IDLE SPEED ADJUSTMENT--Ill
Recheck for proper idle mixture setting,,
NOTE: It may be necessary to repeat Idle
Speed Adjustment-t and Low Speed Mixture
Adjustment
7. CHECK ACCELERATION
Adjust if there is a slight hesitation, by turn-
ing the Low Speed Mixture Screw 1/16 of a
turn at a time counterclockwise _ un-
til you have smooth acceleration,
NOTE: Check to be sure the chain is not turn-
ing when engine is idling. If chain moves at
idle speed, repeat Idle Speed Adjustment-ll
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