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D.
CARBURETOR
AD3USTM
ENlrS
• The carburetor has been adjusted at the factory for
sea level conditions. Adjustments may become
necessary if the unit is used at significantlyhigher
altitudesorjfyounoticeanyofthe following conditions.
NOTE: Be sure to propedy p_,_i)are the saw as
describedin "1. Preparation" below,beforemaking
any adjustments.
--Chain
moves when the engine runs at idle
speed. See "2. Idle Speed Adjustment:'
-- Saw will not idle. See "2. Idle Speed Adjust-
ment" and "3. Low Speed Mixture Adjust-
ment."
-- Loss of cuffing power which is not corrected by
a|r filtercleaning, "See "5. High Speed Mixture
Adjustment."
Engine dies or hesitates when itshould accel-
ICAUTION: I Permanent damage will occur to any
2-cycle engine if incorrect carburetor adjust-
merits are made,
•
If the unit will not operate properly after making
these adjustments, take the unit to•your Sears
Service Center.
A_,WARNING
The chain may be moving during most of this pro_.
eedure. Wear your protective gear and observe all
safety precautions.
!, PREPARATION
a. Stop engine.
': _?b.Use a fresh fuel mixture with proper gasoline/oil
ratio. See "Fueling YourEngine".
c. Placethe sawon asofid,flatsurfaceand make sure
the chain will not contact any object.
d. Locate the three (3) carburetor adjusting screw
openingsto therightofthe airfiltercover.F_jure 52.
e. Startthe engine and allowengine to idle3 minutes
to warm up. The engine must be at operating
temperature for proper adjustments to be made.
IDLE
SPEED ADJ. SCREW'
F_gure 52
2. IDLE SPEED ADJUSTMENT
a. Allow engine to idle.
r
bw
AdjustIdle Speed Screwuntilenginecontinues|o
run withoutstallingandwithout the chain moving
Turn screw clockwise _
to increase
engine speed if enginestallsor dies.
Turnscrew counterclockwise It.._
to slow
engine down and!or to keep the chain from
turning.
c.-No further adjustments are necessary if the
chain does not move at idlespeed and if perfor-
mance is satisfactory.
J
_WARNING
Recheck idle speed after each adjustment below. The
.,chainmustnotmoveatidle
speed to avoid serious
injury.
3. LOW SPEED MIXTURE ADJUSTMENT
a. Allow engine to idle.
b Turn the Low Speed Mixture Screw slowly
clockwise _
until the RPM starts to drop.
Note the position.
c. Turnthe Low Speed Mixture Screw counterclock-
wise _
untilthe RPM speeds up and sta_s
to drop again• Note the position.'
d. Set the Low Speed Mixture Screw at the m_d-
_int between the two positions.
4. ACCELERATION
ADJUSTMENT
Ifengine dies or hesitates instead ofaccelerating, turn
the Low Speed Mixture Screw 1/16ofatum at atime
counterclockwise _
until you have smooth
acceleration.
5. HIGH SPEED MIXTURE ADJUSTMENT
ICAUTION: I Adjustments
as small as 1/16 of a
.turn can affect engine performance, It is Impor-
tant totum the screw only 1/16of a turn per adjust-
ment and test the performance of the saw before
making further adjustments.
a. Make a test cut.
b. Adjust the High Sl_._lMixture S_'ew 1/16ofatum
as follows:
--CloCkwise
_
ifsawsmokesorlesespower.
-- Counterclockwise _
if the saw has speed
out of the cut but lackspower in the cut.
c. Repeat test cut.
d. Continue 1/1.6 of a turn adjustmentsuntilthe saw
runs smoothly in cut.
JCAUTION: I A too lean high speed setting (clock-
wise _
adjustment)willcauseenginedam-
age to any 2-cycle engine fror_ overheating and
lack of lubrication.
Never set the high speed mix-
ture screw so far clockwise _
thatyouhave
high engine speed but lack power while cutting.
An effective approach follows:
Turn screw
counterclockwise
_until
engine loses power while cutting.
Then, turn screw clockwise _
in 1116of a
turn increments only until the engine has
power while cutti_l.
NOTE: If the unit will not operate propedy after
makingthese adjustments,takethe unittoyourSears
Service Center,
21
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