Craftsman 358.798270-32ce Important Manual page 19

D. CARBURETOR ADJUSTMENTS
N__D__TFA This is a complicated task. Read all warnings and instructions thoroughly before starting ad-
justments. If you do not think that you completely understand all warnings and instructions, let your
Authorized Service Dealer perform these adjustments.
DANGER
.Make carburetor adjustments with the lower
end supported to prevent blade or trimmer line
from contacting any object. Hold unit with your
hand,, do not use optional shoulder strap for sup.
port.
A WAltZING
_eep others away when making carburetor ad-
ustments.
A WARNn G [
Serious injury to the operator and others can oc- |
cur if the carburetor is not properly adjusted. J
• Poor engine performance can be a result of
other causes such as dirty air filter, carbon
build-up on muffler outlets, etc. See
"Trouble Shooting Chart" before proceed-
ing with carb_tretor adjustments.
• The carburetor has been carefully adjusted
at the factor_ However, the operator must
be sure that a_ustments are made when
any of the con .ditions occur as mentioned on
the next page m "Trouble Shooting 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. TROUBLE SHOOTING SUGGESTIONS
- Engine will not continue to run at idle posi-
tion. See "Idle Speed Adjustment" and "Low
Speed Mixture Adjustment."
- Blade or trimmer head continues to spin when
the engine idles. See "Idle Speed Adjustment"
and "Deceleration Check."
- Engine dies or hesitates when it should accel-
erate. See "Acceleration Chec_"
, Loss of cutting power which cannot be cor-
rected by cleaning the air filter. 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, ff the carburetor requires ad-
justment, begin with "Basic Carburetor Set-
tings."
2. BASIC CARBURETOR SETTINGS
_T_ In most cases, your engine can be made to
run properly with minor carburetor adjustments.
Refer to "Trouble Shooting Suggestions" in the
lef_ column for the condition you are experiencing
and follow the instructSons. The basic carburetor
settings are provided below.
a. Turn thelow speed mixture screw and the high
speed mix, re screw (Figure 25 ) clockwise
until they stop. Do not turn the screws until
they are tight as damage to the needle seatz can
occur.
b. Turn the low S_eed mixture and high speed
mixture screws between three-quarters and
one fi_ turn counterclockwise.
3. ADJUSTING PROCEDURE
a. PREPARATION
1. Useafresh fuelmix. See"FuelingYourEn-
gme,"
2. Make sure the line extends to the length al-
lowed by the line limiter to provide correct
load on engine.
3. Startthe engine. Cut grass for 3 minutes to
warm enghle. The engine must be at operat-
ing temperature before carburetor ddjust-
ments can be performed correctly,
b, IDLE SPEED ADJUSTMENT
1, Allow engine to idle,
2. Adjust idle speed screw (Figure 25 ) until
engine continues to run without stalling
and without blade or trimmer head moving.
- Turn screw clockwise to increase engine
speed if the engiae stalls or dies.
- Turn screw counterclockwise to slow en-
gine down and/or to keep blade or trim,
mer head from turning.
3, Follow instructions in 'Ykcceleration
Check" and "Deceleration Check."
4. No further adjustments are necessary
if the blade or trimmer head does not
turn at idle speed and if performance
is satisfactory.
c. ACCELERATION CH_CK
1. Allow engine to idle.
2. Squeeze trigger fully
v_ If performance is satisfactor_ pro-
ceed to "d. Deceleration Check,"
b. If the engine does not accelerate
smoothl_ turn the low speed mixture
screw (Figure 25 ) counterclockwise a
small amount (no more than the width
of the slot in the adjusting screw).
3. Repeat step "2.)" until smooth acceleration
is obtained.
It ma_ be necessary to repeat "Idle Speed
Adjustment through _cceleration Check, to
obtain correct adjustments.
4. Follow instructions in "Deceleration
Check."
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