Owner`s manual

D. CARBURETOR""ADJusTMENTS
• The carburetor has been adjusted at the fac-
tory for sea levet conditions. Adjustment may
become necessary if the unit is used at
significantJy 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,
inn.
--Engine dies or hesitates when it should
accelerate.
•• Permanent_damage will occur to the engine if
•,_i,r_,_qrrectcarburetor adjustments are made,/t
is best to let your SEARS Service Center make
'carburetor adjustments.. If you choose to
• make the adjustment ¥ourself,.observe .the
f0]lowing procedure very Carefully.
WARNING]
Thechbirl_fnay be moving during this prbcedure,
Wear your protective gear and observe all safety
precautions.
1. PREPARATION
a. Stop :engine.
b, Use a fresh fuel mixture With proper
gasolineloi! ratio.
c. Place thesaw on a solid, fiat surface and
make sure the chain wil| not contact any
object.
d. Dust off the carburetor cover and surround-
ing area to remove debris which might fall
into the carburetor chamber.
e. Remove the carburetor,cover 'screws and
carburetor cover. Figure 55.
f. Find the three (3)carburetor adjusting
screws. Figure 54.
g. Turn the Low Speed Mixture Screw and the
High Speed Mixture Screw clockwise just
,. ,,,:!!_Jntil_theystop, Do not turn the screws unti/
• _-_!i:__:theyare:,tight _as you may,_damage ,the nee-
,:die seats.
h: Turn the Low Speed Mixture Screw and the
.......High,Speed. Mixture Screw one full turn
counterclockwise
CHOKE CLOSED
HIGH SPEED
MIX SCREW
IDLE SPEED LOW SPEED
SCREW MIX SCREW
=_
Figure 54
2. IDLE SPEED ADJUSTMENTwl
a. Start the engine,
b. Adjust if the engine stops (when the trigger
is not squeezed) by turning the idle Speed
Screw.l!2 turn clockwise
NOTE: To increase idle speed, turn the Idle
Speed Screw clockwise _ , To
decrease idle speed, turn the idle Speed
Screw counterclockw se _
c, Run the engine for a few minutes td bring it
up to operating t,emperature,
NOTE: The engine must be at=:operating
temperature for proper adjustmeflts'to be
made.
3. LOW SPEED MIXTURE ADJUSTMENT
a, Turn. the Low Speed Mixture Screw-slowly
clockwise, :._--Jl_-unti! the RPM starts to
..... :.drop. Note ,the position. _:
b: Tdrn the,_.Low_Speed :Mixture. Scr,_-coun-
terclockwise _ until the RPM_speeds
up and starts to drop again. Note the posi-
tion.
c. Position the Low Speed Mixture Screw at
the mid-point between the two positions,
4, IDLE SPEED ADJUSTMENT--I!
a. Allow engine to idle:
b. Adjust if the chain is turning by turning the
Idle Speed Screw counterclockwise _.
c. Squeeze the throttle trigger;, the saw
should accelerate without hesitating.
NOTE: It maybe:necessary to:recheck the
low speed mixture setting after the idle
speed has been reduced by repeating Low
Speed Mixture ,Adjustment Steps.
5, HIGH SPEED MIXTURE ADJUSTMENT
. a:.Make a,test cut.
NOTE::.Take:,st_ec!a_car_e to keep chips and
dirt" out of, the carburetor.
b. Adjust if the saw smokes or Seems to have
low power in the test cut by turning the
.... -:.:High Speed,. Mixture Screw _1./16th turn
clockwise
c, Repeat test cut.
d. Repeat adjustment until the saw rur_s
smoothly.
CAUTION: Never set the High-Speed Mix.
lure Screw less. than 718 turn operL This is
too lean a setting and-will ruin your engine,
6. IDLE SPEED ADJUSTMENT--Ill
Recheck for proper idle mixture setting.
NOTE: It may be necessary to repeat ac-
cording to instructions in Steps 2 and 3,
Idle Speed Adjustment--I and Low Speed
Mixture Adjustment.
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