Cub Cadet ST2020 Operator's Manual page 12

AIR FILTER MAINTENANCE
Removing the Air Filter/Muffler Cover
WARNING:
To avoid serious personal injury, always turn
your unit off and allow it to cool before you clean or service it.
1. Place the blue choke lever in Position 2.
2. Remove the four (4) screws securing the air filter/muffler cover (Fig. 24).
Use a flat blade or T20 Torx bit screwdriver.
3. Pull the cover from the engine. Do not force.
Screws
Cleaning the Air Filter
Failure to maintain your air filter properly can result in poor performance or
can cause permanent damage to your engine.
1. Remove the air filter/muffler cover. Refer to Removing the Air Filter/
Muffler Cover.
2. Turn cover over and look inside to locate the air filter. Remove the air
filter from inside the air filter/muffler cover (Fig. 25).
3. Wash the filter in detergent and water. Rinse the filter thoroughly.
Squeeze out excess water. Allow it to dry completely.
4. Apply enough clean SAE 30 oil to lightly coat the filter.
5. Squeeze the filter to spread and remove excess oil.
6. Replace the air filter inside the air filter/muffler cover (Fig. 25).
NOTE: Operating the unit without the air filter and air filter/muffler cover
assembly will VOID the warranty.
Reinstalling the Air Filter/Muffler Cover
1. Place the air filter/muffler cover over the back of the carburetor and
muffler. Align the screw holes.
2. Insert the four (4) screws into the holes in the air filter/muffler cover (Fig. 24)
and tighten.
Do not over tighten.
12
MAINTENANCE AND REPAIR INSTRUCTIONS
Blue Choke Lever
Screws
Fig. 24
Air Filter
Inside Muffler C over
Fig. 25
IDLE SPEED ADJUSTMENT
The idle speed of the engine is adjustable through the air filter/muffler cover
(Fig. 26).
NOTE: Careless adjustments can seriously damage your unit. An
authorized service dealer should make carburetor adjustments.
If, after checking the fuel mixture 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.
WARNING:
The cutting head may spin during idle speed
adjustments. Wear protective clothing and observe all safety
instructions to prevent serious personal injury.
2. Release the throttle trigger and let the engine idle. If the engine stops,
insert a small Phillips or flat blade screwdriver into the hole in the air
filter/muffler cover (Fig. 26). Turn the idle speed screw in, clockwise,
1/8 of a turn at a time (as needed) until the engine idles smoothly.
NOTE: The cutting head should not rotate when the engine idles.
3. If the cutting head rotates when the engine idles, turn the idle speed
screw counterclockwise 1/8 of a turn at a time (as needed), to reduce
idle speed.
Checking the fuel mixture, cleaning the air filter, and adjusting the idle speed
should solve most engine problems.
If not and all 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.
WARNING:
To prevent serious personal injury, make sure
the cutting head has stopped rotating before you turn it off and
set it down.
Idle Speed Screw
Fig. 26