Craftsman 917.28808 Operator's Manual page 28

TO ADJUST CARBURETOR
NOTE: The carburetor on this engine is
low emission. It is equipped with an idle
fuel adjusting needle with a limiter cap,
which allows some adjustment within the
limits allowed by the cap. Do not attempt
to remove the limiter cap. The limiter cap
cannot be removed without breaking the
adjusting needle.
The carburetor has been preset at the
factory and adjustment should not be
necessary. However, minor adjustment
may be required to compensate for dif-
ferences in fuel, temperature, altitude or
load. If the carburetor does need
adjustment, proceed as follows:
In general, turning idle mixture valve in
(clockwise) decreases the supply of fuel to
the engine giving a leaner fuel/air mix-
ture. Turning the idle mixture valve out
(counterclockwise) increases the supply
of fuel to the engine giving a richer fuel/air
mixture.
IMPORTANT: Damage to the needle
valve and the seat in carburetor may result
if screw is turned in too tight.
PRELIMINARY SETTING -
1. Air cleaner assembly must be assem-
bled to the carburetor when making
carburetor adjustments.
2. Be sure the throttle control cable is
adjusted properly (see above).
F I NAL SETTI N G - (See "TO ADJUST
THROTTLE CONTROL CABLE" in this
section of the manual.)
1. Start engine and allow to warm for five
minutes. Make final adjustments with
engine running and shift/motion control
lever in neutral (N) position.
.
.
Move throttle control lever to slow posi-
tion. With finger, rotate and hold throttle
lever against idle speed screw. Turn
idle speed screw to attain 1750 RPM.
While still holding throttle lever against
idle speed screw, turn idle mixture
valve full travel clockwise then counter-
clockwise until engine runs rough. Turn
valve to a point midway between those
two positions. Release throttle lever.
ACCELERATION TEST -
4. Move throttle control lever from slow
to fast position. If engine hesitates or
dies, turn idle mixture valve out (coun-
terclockwise) 1/8 turn. Repeat test and
continue to adjust, if necessary, until
engine accelerates smoothly.
High speed stop is factory adjusted. Do
not adjust or damage may result.
IMPORTANT: Never tamper with the
engine governor, which is factory set
for proper engine speed. Overspeeding
the engine above the factory high speed
setting can be dangerous. If you think the
engine-governed high speed needs adjust-
ing, contact a Sears or other qualified ser-
vice center, which has proper equipment
and experience to make any necessary
adjustments.
Idle Speed r- _ ''-.. .....
Screw Thvr°t[le
Idle Mixture / _ I _ i
Valve with / _ J _ I
Limiter _
Immediately prepare your tractor for stor-
age at the end of the season or if the trac-
tor will not be used for 30 days or more.
_,CAUTION: Never store the tractor
with gasoline in the tank inside a building
where fumes may reach an open flame
or spark. Allow the engine to cool before
storing in any enclosure.
TRACTOR
Remove mower from tractor for winter
storage. When mower is to be stored for a
period of time, clean it thoroughly, remove
all dirt, grease, leaves, etc. Store in a
clean, dry area.
1. Clean entire tractor (See "CLEANING"
in the Maintenance section of this
manual).
2. Inspect and replace belts, if necessary
(See belt replacement instructions in
the Service and Adjustments section of
this manual).
3. Lubricate as shown in the Maintenance
section of this manual.
4. Be sure that all nuts, bolts and screws
are securely fastened. Inspect moving
parts for damage, breakage and wear.
Replace if necessary.
5. Touch up all rusted or chipped paint
surfaces; sand lightly before painting.
28