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D. CARBUF TOR
ADJUSTMENTS
YOITR CRAFTSMAN
PRODUCT
HAS
BEEN
DESIGNED
AND
MANUFACTURED
TO
SPECIFI-
CATIONS
THAT .P_DUCE
_
EMISSIONS.
A_er
your unit has been run for 5 hours,
the en-
gine has broken
-m"
To ensure
that your unit is at peak perfo,rmance
and producing
the least amount
of harmful
ennsslons
after
b.reak-m,
have your SEARS
Service
Center/Department
adjust your car-
buretor
for optimum
operating
conditlous.
NOTE.. Properly
adjusting
the carburetor
is a complicated
task. Read all warnings
and instructions
vbefore
starting
adjustments.
If you do not think that you completely
understand
all warn.
let _'our SEARS
Service
Center/Department
perform
these
adjustments.
A
WARNING
2, BASIC
CARBURETOR
SETNNGS
carburetor
adjustments
with
the
lower
end supported
to prevent
the trimmer
Hne from
contacting
any object. Hold tool with your hand;
do not use optional
shoulder
strap for support.
Keep others
away when
making
carburetor
ad-
ljustments.
A WARNING
Serious
injury to the operator
and others
can oc-
cur if the carburetor
fs not properly
adjusted.
•
P0orengine
performance
canbe
aresult
of
other
causes
such as dirty air filter, carbon
build-up
on
muffler
outlets,
etc.
:See
"Trouble
Shooting
Chart"
before
proceed-
ing with
carburetor
adjustments.
• The carburetor
has been carefully
adjusted
at
the factory.
However,
the operator
must
be sure
that
adjustments
are made
when
any of the conditions
occur as mentioned
on
the next page
in "Troubleshooting
Sugges.
tions".
•
Very small
adjustments
can
affect
engine
performance.
It is important to turn the screw a
, very small amount per adjustment
and test per-
formance
before
making
further
adjustments.
Each adjustment
should be no more than the
width of the slot in the adjusting screw.
•
This
is a complicated
task and it is impor-
tant
to follow
instructions
in sequence
as
indicated.
1. TROUBLESHOOTING
SUGGESTIONS
-
Engine will not continue
to run at idle posi-
tion. See "Idle Speed Adjustment"
and "Low
Speed Mixture
Adjustment.
-
Trimmer head continues to spin when the en-
Fine idles. See "Idle Speed Adjustment"
and
"Deceleration
Check,"
-
Engine dies or hesitates when it should accel-
erate. See '_kcceleration
Check."
Loss of cutting power which cannot be cor-
rected by cleaning
the air fflten
See "High
Speed Mixture Adjustment."
-Engine
does not return to idle from full throt-
tle
within
2
seconds.
See
"Deceleration
Check."
-
Engine will not run.
See "Trouble
Shooting
Chart." Then, if the carburetor
requires ad-
justment,
begin with "Basic Carburetor
Set-
tings."
.
[ The trimmer
line will be spinning
during most of
[this procedure.
Wear your protective
equipment
[ and observe
all safety
instructions.
- 15 -
NOTE." In most cases, your engine can be made to
run properly with minor carburetor adjustments.
Refer to "Trouble
Shooting Suggestions"
in the
left column for the condition you are experiencing
and follow the instructions.
The basic carburetor
settings are provided below.
a. Turn.the low speed mixture screw and the high
....
speed
mixture
screw (Figure24)
clockwise
until
they stop. Do not turn screws until they
are tight as damage to needle seats can occur.
b. Turn
the low speed mixture
and high speed
mixture
screws between
three-quarters
and
one full turn counterclockwise.
3. ADJUSTING
PROCEDURE
a. PREPARATION
1. Use fresh fuel mix. See Fueling
section.
2. Make sure the line extends to the length al-
lowed by the line limiter to provide correct
toad on engine.
3. Start the engine. Cut grass for 3 minutes to
warm engine. The engine must be at operat-
ing temperature
before carburetor
adjust.
ments can be performed
correctly.
b. IDLE SPEED ADJUSTMENT
1. Allow engine to idle.
2. Adjust idle speed screw (Figure 24 ) until
the engine continues
to run without
stall-
:
ing and without
the trimmer head moving.
- Turn screw clockwise to increase engine
speed
if the engine stalls or dies.
- Turn screw counterclockwise
to slow en-
gine down and/or to keep trimmer
head
from turning.
3. Follow
instructions
in
'_cceleration
Check" and "Deceleration
Check."
4. No further
adjustments
are necessary
if trimmer
head
does not turn at idle
speed and performance
is satisfactor_
A WARNING
[
Re. check idle speed
after
each adjustment.
The
trimmer
head
must
not turn
at idle speed
to
avoid se_0us
in_ur_ to the operator
andothers.
c. ACCELERATION
CHECK
1. Allow engine to idle.
2. Squeeze trigger fully
a.) If performance
is satisfactor_
pro-
ceed to "d. Deceleration
Check."
b.) If the engine
does
not
accelerate
smoothi_
turn the low speed mixture
screw (Figure 24 ) counterclockwise
a
small amount
(no more" than the width
of the slot in the adjusting
screw).
3. Repeat step "b.)" until smooth acceleration
is obtained.
NOTE:
It may be necessary
to repeat "b. Idle
Speed ,,A_'ustment"
through
"c. Acceleration
Check,
to obtain correct adjustments.
4. Follow
instructions
in "d.
Deceleration
Chect_"
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