Maintenance And Repair Instructions - Cub Cadet ST426s Operator's Manual

MAINTENANCE SCHEDULE
WARNING:
To prevent serious injury, never perform
maintenance or repairs with unit running. Always service and
repair a cool unit. Disconnect the spark plug wire to ensure that
the unit cannot start.
Perform these required maintenance procedures at the frequency stated in
the table. These procedures should also be a part of any seasonal tune-up.
NOTE: Some maintenance procedures may require special tools or skills.
If you are unsure about these procedures take your unit to any
non-road engine repair establishment, individual or authorized
service dealer.
NOTE: Maintenance, replacement, or repair of the emission control
devices and system may be performed by any non-road engine
repair establishment, individual or authorized service dealer.
NOTE: Please read the California/EPA statement that came with the unit
for a complete listing of terms and coverage for the emissions
control devices, such as the spark arrestor, muffler, carburetor, etc.
FREQUENCY MAINTENANCE REQUIRED
Every 10 hours Clean and oil air filter
After first 10 hours Change oil
Change oil
Every 40 hours Check rocker arm to valve clearance and adjust
Check spark plug condition and gap
REMOVING THE LINE
1. Rotate the bump knob clockwise until all line
is inside the cutting head (Fig. 19).
2. Using a flat-head screwdriver, insert the tip
into the line dimple and just under the
exposed portion of the line (Fig. 20)
3. Pull the line straight out until all line is
removed from the cutting head.
LINE INSTALLATION
Always use original equipment manufacturer
0.095 in. (2.41 mm) replacement line.
1. Align the arrows on the bump knob with the
spool cover eyelets, if they are not already
(Fig. 21).
2. Using 10 ft. (3 m) of 0.095 in. (2.41 mm)
replacement line push both ends of the line
through the holes in the bump knob until they
protrude through the eyelets on both sides of
the cutting head. Continue pulling the line
until approximately 5 ft. (1.5 m) is visible from
both sides of the cutting head. (Fig. 22)
3. Hold the spool cover, turn the bump knob
clockwise to wind the line around the spool
until about 5 in. (12.7 cm) is protruding from
each side of the cutting head. (Fig. 19)
4. Start the unit and bump the cutting head on
the ground until the desired cutting length is
achieved. Excess line will be trimmed off by
the line blade.
NOTE: If the cutting line ends are pulled into
the cutting head or the line becomes
twisted, refer to Removing the Line.
CHECKING THE OIL LEVEL
WARNING:
To prevent extensive
engine wear and damage to the
unit, always maintain the proper oil
level in the crankcase. Never
operate the unit with a low oil level.
The importance of checking and maintaining the
proper oil level in the crankcase cannot be
overemphasized. Check oil before each use:
1. Stop the engine and allow oil to drain into
the crankcase.
2. Place the unit on a flat, level surface to get a proper oil level reading.
3. Keep dirt, grass clippings and other debris out of the engine. Clean the
area around the oil fill plug before removing it.
8

MAINTENANCE AND REPAIR INSTRUCTIONS

SEE
p. 8
p. 8
p. 8
p. 9
p. 9
Bump Knob
Fig. 19
Flat-Head
Screw
Driver
Trimmer
Line
Dimple
Fig. 20
Arrows
Eyelet
Fig. 21
Trimmer line
Fig. 22
Oil Fill Plug
O-Ring
Fig. 23
4. Remove the oil fill plug.
5. Check the oil level. Oil should be just to the
bottom of the threads of the oil fill hole.
(Fig. 24).
6. If the level is low, add a small amount of oil
to the oil fill hole and recheck (Fig. 24).
Repeat this procedure until the oil level
reaches the bottom of the threads in the oil
fill hole.
NOTE: Do not overfill the unit.
NOTE: Make sure the O-ring is in place on the
oil fill plug when checking and
changing the oil (Fig. 23).
CHANGING THE OIL
CAUTION:
Wear gloves to prevent
injury when handling the unit.
Change the oil while the engine is still warm. The
oil will flow freely and carry away more impurities.
1. Remove the oil fill plug.
2. Pour the oil out of the oil fill hole and into a
container by tipping the unit to the side (Fig.
25). Allow ample time for complete drainage.
3. Wipe up any oil residue on the unit and clean
up any oil that may have spilled. Dispose of
the oil according to federal, state and local
regulations.
4. Refill the crankcase with 2.2 fl.oz. (60 ml) of SAE 30 SF, SG, SH oil.
NOTE: Use the bottle and spout saved from initial use to measure the
correct amount of oil. The top of the label on the bottle measures
approximately 3.4 ounces (100 ml) (Fig. 26). Check the level (Fig.
24). If the level is low, add a small amount of oil and recheck. Do
not overfill (Fig. 24).
5. Replace the oil fill plug.
AIR FILTER MAINTENANCE
WARNING:
To avoid serious
personal injury, always turn the unit
off and allow it to cool before you
clean or service it.
Cleaning the Air Filter
Failure to maintain the air filter properly can
result in poor performance or can cause
permanent damage to the engine.
1. Open the air filter cover by pressing the lock
tab in and pulling out on the air filter cover
(Fig. 27 & 25).
2. Remove the air filter (Fig. 29).
3. Wash the filter in detergent and water. Rinse
the filter thoroughly and allow it to dry.
4. Apply enough clean SAE 30 motor oil to
lightly coat the filter.
5. Squeeze the filter to spread and remove
excess oil.
6. Replace the air filter into the base plate
(Fig. 29).
NOTE: If the unit is operated without the air
filter, you will VOID the warranty.
7. Reinstall the air filter cover. Position the two small tabs on the air filter
cover into the two slots in the back plate and press the air filter cover
down, making sure to align the lock tab with the lock tab slot, until it
snaps into place (Fig. 28 & 27).
IDLE SPEED ADJUSTMENT
WARNING:
The cutting
attachment may spin during idle
speed adjustments. Wear protective
clothing and observe all safety
instructions to prevent serious
personal injury.
The idle speed of the engine is adjustable. An
idle adjustment screw is between the air filter
cover and the engine starter housing (Fig. 30).
Add 1.4-1.5
Oz.
(41-44 ml)
Oil Fill Hole
Fig. 24
Fig. 25
Fill
Level
Fig. 26
Air Filter Cover
Air Filter
Cover Tab
Fig. 27
Air Filter Back Plate
Cover
Fig. 28
Back
Plate
Air Filter
Fig. 29
Idle
Adjustment
Screw
Fig. 30