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Adjusting the Carburetor
Differences in fuel, temperature, altitude or load may
require minor carburetor adjustments. The carburetor
on this engine is equipped with an idle mixture valve
with a limiter which allows some adjustment, and an
idle speed adjustment screw. Remember that the air
cleaner must be assembled to the carburetor before re-
starting the engine. Refer to page 14 for details.
NOTE: Engines, operated at approximately 3000 to
5000 feet above sea level, may require a high altitude
carburetor nozzle. If your riding mower performs
erratically, contact Sears service center for the nozzle.
To adjust the carburetor, follow the steps below:
1.
Start the engine and run it for at least 5 minutes to
warm up.
2.
With the engine running, place throttle control in
SLOW position.
3.
Lift the hood assembly up as instructed on page 7.
4.
Remove the black cap from the rider frame. See
Figure 16. Access the carburetor throttle lever and
idle speed screw from this opening.
IDLE MIXTURE
VALVE
WITH
LIMITE
R
Carbureto/r
Throttle
Lever
Figure 16
5.
Rotate carburetor throttle lever against the idle
speed screw and hold it. Turn idle speed screw to
obtain 1750 rpm, using a tachometer to measure.
6.
Rotate idle mixture valve full travel clockwise and
then counter-clockwise.
Do NOT remove limiter
caps. Do NOT force beyond limits.
7.
Place idle mixture valve in middle of travel.
8.
Move throttle control to FAST position. The engine
should accelerate smoothly. If it does not, adjust
idle mixture valve counter-clockwise
1/8 turn.
9.
Replace the black cap on the riding mower frame
and put the hood assembly back.
Fuse Replacement
The fuse is located next to the spark plug under the rear
frame. Fuses seldom fail without a reason. If the fuse
blows, the source problem must be corrected or the
new fuse wilt blow again.
1.
Check for loose connections in the fuse holder and
replace holder if necessary. A dead short may be in
the cranking or charging circuit where insulation
may have rubbed through and exposed bare wire.
2.
Replace the wire or repair with electrician's tape if
the wire strands have not been damaged. Also look
for a wire pinched between body panels, burned by
the exhaust pipe or muffler, or rubbed against a
moving part.
3.
Stop the riding mower and engage the parking
brake. Remove ignition key.
4.
Pivot the hood assembly up. Disconnect the spark
plug wire and ground it.
5.
Pull the fuse out of the lead wire.
6.
Replace with new automotive fuse.
7.
Make sure to reconnect the spark plug wire before
pivoting the hood assembly back.
Belt Replacement
There are two drive belts and one deck belt in this unit;
follow description below to identify the belts.
•
Deck belt goes from the deck pulley to the lower
sheave in engine pulley.
•
Lower drive belt goes from the variable speed
pulley to the transmission pulley.
•
Upper drive belt goes from the variable speed
pulley to the upper sheave of engine pulley.
Periodically check if these belts are too loose or
damaged. If so, replace with new belt.
Deck Belt
1.
Engage the parking brake and turn the ignition off.
Pivot the hood assembly up and remove the grass
catcher. Remove the spark plug wire.
2.
Put the deck at the lowest cutting height by
adjusting the cutting height adjustment lever to the
lowest position.
Imaginary
Belt
Line
Belt
Keeper "A"
ut
Pulley
Screw
Pulley
Figure 17
19
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