Cub Cadet ST226 Operator's Manual page 5

MAINTENANCE AND REPAIR INSTRUCTIONS
LINE INSTALLATION
Always use original equipment manufacturer 0.095 in. (2.41 mm)
replacement line. Other types of line may make the engine overheat or fail.
NOTE: There may be a need to remove the old line prior to
installing new line. If so, please refer to Removing the
old line or obstructions.
1. Align the arrows on the cutting head knob with the
outerspool eyelets, if they are not already.(Fig. 12)
2. Using 10.5 ft. (3.2 m) of 0.095 in. (2.41 mm) replacement line push
an end of the line through one of the eyelets until it protrudes
through the opposite side. Continue pushing or pulling the line
until the line is evenly distributed, so approximately 5 ft. (1.5 m) is
visible from both sides of the cutting head.(Fig. 13)
3. Hold the cutting head knob and turn the cutting head clockwise
to wind the line around the spool until 5 in. (12.7 cm) is
protruding from each side of the cutting head.(Fig. 14)
NOTE: If winding the line from a large spool of line, cut the line
from the spool so that it measures 5" from the eyelet.
4. Start the unit and bump the cutting head on the ground
until the desired cutting length is achieved.
REMOVING THE OLD LINE OR OBSTRUCTIONS
NOTE: There should only be a need to remove the bump cap if
the old line gets jammed or an obstruction preventing the
new line from being installed properly.
1. Firmly press in on the tabs that are on each side of the
cutting head. (Fig. 15)
NOTE: It may be easier to press in and then up on one tab at a time.
2. Remove the cap either by letting it pop off or a slight wiggle of
the cap may be required and pull it off the outer spool (Fig. 16)
3. Unwind the old line from the inner reel and any obstructions
by removing it from the outer spool. (Fig. 17)
4. Place the inner reel back into the outer spool (Fig. 16).
NOTE: When placing the inner reel back into the outer spool,
make sure the side with the L is facing up towards the bump cap.
5. Replace the bump cap by aligning the tabs of the bump cap with the lock windows of the outer
spool and press down firmly until both tabs snap back into place. (Fig. 12 & 18)
To install new line, please refer to the Line Installation section.
Tab
Fig. 15
Fig. 17
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
Clean the air filter every 10 hours of operation. It is an important
item to maintain. Failure to maintain your air filter properly can
result in poor performance or can cause permanent damage to
your engine.
1. Open the air filter cover by unscrewing the air filter screw
(Fig. 19).
2. Remove the air filter (Fig. 22).
3. Wash the filter in detergent and water (Fig. 21). Rinse the
filter thoroughly and allow it to dry.
4. Replace the air filter into the base plate (Fig. 22).
NOTE: If the unit is operated without the air filter, you will
VOID the warranty.
5. Reinstall the air filter cover. Position the hooks on the air filter
cover to the top of the back plate and lower the air filter cover
down so that the air filter screw aligns with the screw hole
on the back plate (Fig. 20).
6. Turn the air filter screw clockwise until the air filter screw is tight (Fig. 19).
NOTE: Do not over tighten as this may strip the screw.
Fig. 21
Arrow
Eyelet
Fig. 12
Fig. 13
Fig. 14
Bump Cap
UP
Inner
Reel
Spool Lock
Outer Spool
Cutting
Head
Knob
Fig. 16
PRESS
Fig. 18
Air Filter Cover
Air Filter
Screw
Fig. 19
Air Filter Cover
Back Plate
Fig. 20
Back Plate
Air Filter
Screw Hole
Fig. 22
MAINTENANCE AND REPAIR INSTRUCTIONS
CARBURETOR 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. 23).
NOTE: Careless adjustments can seriously damage your
unit. An authorized service dealer should make
carburetor adjustments.
Check Fuel
Old fuel is usually the reason for improper unit performance. Drain and refill the tank with fresh fuel mixture
prior to making any adjustments. Refer to Oil and Fuel Information.
Clean Air Filter
The condition of the air filter is important to the operation of the unit. A dirty air filter will restrict air flow.
This is often mistaken for an out of adjustment carburetor. Check the condition of the air filter before
adjusting the idle speed screw. Refer to Air Filter Maintenance.
Adjust Idle Speed Screw
If, after checking the fuel and cleaning the air filter, the engine still will not idle, adjust the idle speed screw
as follows:
1. Start the engine and let it run at a high idle for a minute to warm up. Refer to Starting/Stopping
Instructions.
2. Release the throttle trigger and let the engine idle. If the engine stops, locate the idle screw between
the air filter and starter housing (Fig. 23). Using a small phillips or flat blade screwdriver, turn the idle
speed screw, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly.
NOTE: The cutting attachment should not rotate when the engine idles.
3. If the cutting attachment rotates when the engine idles, turn the idle speed screw
counterclockwise 1/8 of a turn at a time (as needed), until the engine idles smoothly without the
cutting attachment rotating.
Checking the fuel, cleaning the air filter, and adjusting the idle
speed should solve most engine problems. If not, and any of the
following are true:
• the engine will not idle
• the engine hesitates or stalls on acceleration
• there is a loss of engine power
Have the carburetor adjusted by an authorized service dealer.
REPLACING THE SPARK PLUG
Use a replacement part number 753-05784 spark plug. The
correct air gap is 0.025 in. (0.635 mm). Remove the plug after
every 25 hours of operation and check its condition.
1. Stop the engine and allow it to cool. Grasp the plug wire firmly with a pair of needle nose pliers and
pull the cap from the spark plug.
2. Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a
5/8 in. socket counterclockwise.
WARNING:
Do not sand blast, scrape or clean electrodes. Grit in the engine could
damage the cylinder.
3. Replace cracked, fouled or dirty spark plug. Set the air gap at 0.025 in. (0.635 mm) using a feeler
gauge (Fig. 24).
4. Install a correctly-gapped spark plug in the cylinder head. Turn the 5/8 in. socket clockwise until snug.
If using a torque wrench torque to:110-120 in.•lb. (12.3-13.5 N•m)
Do not over tighten.
CLEANING
Use a small brush to clean off the outside of the unit. Do not use strong detergents. Household cleaners
that contain aromatic oils such as pine and lemon, and solvents such as kerosene, can damage plastic
housing or handle. Wipe off any moisture with a soft cloth.
STORAGE
• Never store the unit with fuel in the tank where fumes may reach an open flame or spark.
• Allow the engine to cool before storing.
• Lock up the unit to prevent unauthorized use or damage.
• Store the unit in a dry, well-ventilated area.
• Store the unit out of the reach of children.
LONG TERM STORAGE
1. Drain all gasoline from the gas tank into a container. Do not use gas that has been stored for more
than 60 days. Dispose of the old gasoline in accordance to Federal, State, and Local regulations.
2. Start the engine and allow it to run until it stalls. This ensures that all gasoline has been drained
from the carburetor.
3. Allow the engine to cool. Remove the spark plug and put 5 drops of high quality motor oil into the
cylinder. Pull the starter rope slowly to distribute the oil. Reinstall the spark plug.
NOTE: Remove the spark plug and drain all of the oil from the cylinder before attempting to start the
trimmer after storage.
4. Thoroughly clean the unit and inspect for any loose or damaged parts. Repair or replace damaged
parts and tighten loose screws, nuts or bolts. The unit is ready for storage.
TRANSPORTING
• Allow the engine to cool before transporting.
• Secure the unit while transporting.
• Drain the gas tank before transporting.
• Tighten gas cap before transporting.
Idle Ajustment Screw
Fig. 23
0.025 in.
(0.635 mm.)
Fig. 24
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