Operating Instructions; Maintenance & Repair Instructions - MTD Yard Machines YM121 Manual Del Operador

OPERATING TIPS
WARNING:
Dress properly to reduce the risk of injury when operating this unit. Do not
wear loose clothing or jewelry. Wear eye and ear/hearing protection. Wear heavy long
pants, boots and gloves. Do not wear short pants, sandals or operate barefoot.
1. Move the cultivator to the work area prior to starting the
engine. Transport the cultivator by pushing it on its wheels.
2. Start the unit as described in the Starting Instructions.
CAUTION:
To prevent serious personal injury,
never pick-up or carry the unit while the engine is
running.
3. With the engine running and the tines off the ground,
depress the throttle control to increase the engine speed.
4. Holding both of the handlebar grips firmly, slowly lower the
cultivator until the tines make contact with the ground (Fig. 8).
5. As cultivating action begins, pull back on the cultivator so
that the tines can penetrate the ground.
6. Once the ground has been broken, continue at a moderate pace until you are familiar with the
controls and the handling of the cultivator.
WARNING: To prevent serious personal injury, use extreme caution when reversing or
pulling the unit towards you.
7. Pull the cultivator backwards to improve the depth of cultivation and reduce your effort.
8. If the tines are digging too deep or not deep enough, adjust them according to Adjusting Tine Depth.
MAINTENANCE SCHEDULE
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.
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.
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.
In order to assure peak performance of your engine, inspection of the engine exhaust port may be necessary
after 50 hours of operation. If you notice lost RPM, poor performance or general lack of acceleration, this
service may be required. If you feel your engine is in need of this inspection, refer service to any non-road
engine repair establishment, individual or authorized service dealer for repair. DO NOT attempt to perform this
process yourself as engine damage may result from contaminants involved in the cleaning process for the port.
FREQUENCY MAINTENANCE REQUIRED
Before starting engine Fill fuel tank with fresh fuel mix
Every 10 hours Clean and re-oil air filter
Every 25 hours Check and clean spark arrestor
Check spark plug condition and gap
Every 50 hours Inspect exhaust port and spark arrestor screen for clogging
or obstruction to assure maximum performance levels.
TINE REMOVAL AND REPLACEMENT
NOTE: All installation instructions are explained from the
operating postion.
All 4 tines should be replaced at the same time because they will
wear evenly through normal use. Work on one side at a time.
WARNING:
To prevent serious personal injury,
always wear heavy gloves when handling the
tines.
1. Press and hold the On/Off Stop Control in the STOP (O)
position and disconnect the spark plug wire.
2. Lay the cultivator back on a flat level surface with the
handles touching the ground so that the cultivator is in a
horizontal postion.
NOTE: It may be necessary to wash any dirt off the tines and
shaft for easier tine removal.
3. Remove the click pin from each end of the tine shaft. Slide
the tines off of the shaft (Fig. 10).
4. Clean and oil the shaft.
5. Slide on the new tines with the hubs facing in towards each other.
Making sure that the rotation arrows are facing the gearbox when
installing the tines on left tine shaft and away from the gearbox for
the right tine shaft. (Fig. 11)
6. Secure the new tines to the shaft with click pins. (Fig. 10)
AIR FILTER MAINTENANCE
WARNING: To avoid serious personal injury,
always turn your unit off and allow it to cool
before you clean or service it.
Removing the Air Filter/Muffler Cover
1. Place the blue choke lever in Position 2.
NOTE: The blue choke lever must be in Position 2 (Fig. 12) to
remove the air filter/ muffler cover.
2. Remove the four (4) screws securing the air filter/muffler
cover (Fig. 12). Use a # T20 Torx bit screwdriver.
3. Pull the cover from the engine. Do not force.
Cleaning the Air Filter
Clean and re-oil 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. Remove the air filter/muffler cover. Refer to the Removing the
Air filter/Muffler Cover section.
2. Remove the air filter from inside the air filter/muffler cover
(Fig. 13).
3. Wash the filter in detergent and water (Fig. 14). Rinse the filter
thoroughly. Squeeze out excess water. Allow it to dry completely.
4. Apply enough SAE 30 oil to lightly coat the filter (Fig. 15).
5. Squeeze the filter to spread and remove extra oil (Fig. 16).

OPERATING INSTRUCTIONS

Fig. 8
MAINTENANCE AND REPAIR INSTRUCTIONS
SEE
p. 4
p. 5
p. 5
p. 6
p. 5
Tine
Left Tine Shaft
Click Pin
Fig. 10
Gearbox
Left Tine
Shaft
Right Tine Shaft
Fig. 11
Blue Choke
Lever
Position 2
Screws
Screws
Fig. 12
Air Filter
Inside Muffler Cover
Fig. 13
ADJUSTING TINE DEPTH
Tine adjustment will vary depending on the type of soil being cultivated and how it will be used.
Generally, adjusting the tines to break the soil 4 to 6 inches is recommended for most gardens. Adjust
the tines as follows:
1. Stop the engine and disconnect the spark plug wire.
2. Loosen (do not remove) the two wing nuts on the tine guard (Fig. 9).
3. Slide the wheel bracket assembly down for shallower penetration, and up for deeper tine
penetration.
4. Once the tines are in the desired position, tighten the wing nuts, making sure that the carriage bolts
are seated properly through the bracket.
5. If the tine depth is incorrect, repeat steps 2 to 4.
6. Reconnect the spark plug wire and continue use.
TRANSPORTING THE UNIT
WARNING:
To prevent serious personal injury,
always stop the engine when operation is
delayed or when transporting the unit from one
location to another
1. Stop the engine.
2. Slide the wheel bracket assembly all the way down.
3. Tilt the unit back until the tines clear the ground.
4. Push or pull the unit to the next location.
6. Replace the air filter inside the muffler cover (Fig. 13).
NOTE: Operating the unit without the air filter and 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.
NOTE: The blue choke lever must be in Postion 2 (Fig. 12) to
remove the air filter/ muffler cover.
2. Insert the four (4) screws into the holes in the air filter/ muffler
cover (Fig. 12) and tighten. Use a # T20 Torx bit screwdriver.
Do not over tighten. Do not force.
SPARK ARRESTOR MAINTENANCE
1. Remove air filter/muffler cover. Refer to Removing the Air
Filter/Muffler Cover.
2. Locate the muffler, but do not remove it. Find the screw on
the bottom of the muffler (Fig. 17). Remove the screw using
either a torx #20 or flat blade screwdriver.
3. Carefully pry up the left side spark arrestor hood. Two tabs
act as hinges on the right side of the hood. Flip open the
spark arrestor hood like a door and then pull its tabs out of
the muffler slots.
4. Using a small flat blade screwdriver, carefully pry the spark
arrestor screen out from the inside of the spark arrestor
hood.
5. Clean the spark arrestor screen with a wire brush. Replace it
if it is damaged, or if you are unable to clean it thoroughly.
6. Reinstall the spark arrestor screen snugly back into the spark
arrestor hood.
7. Reinstall the two hood tabs into the two muffler slots and flip
the spark arrestor hood closed.
8. Replace the screw you removed in Step 2 and tighten it
securely.
9. Reinstall the air filter/muffler cover.
WARNING: If the exhaust deflector assembly
is not tightened securely, it could fall off causing
damage to the unit and possible serious
personal injury.
CARBURETOR ADJUSTMENTS
The engine's idle speed adjuster is adjustable through the air
filter/muffler cover (Fig 18).
NOTE: Careless adjustments can seriously damage your unit.
An authorized service dealer should make carburetor
adjustments.
Check Fuel Mixture
Old and/or improperly mixed fuel is usually the reason for the unit
not running properly. Drain and refill the tank with fresh, properly
mixed fuel 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
and change the air/fuel mixture. This is often mistaken for an out of adjustment carburetor. Check the
condition of the air filter before adjusting the idle speed adjuster. Refer to Air Filter Maintenance.
Adjust Idle Speed Adjuster
If after checking the fuel mixture and cleaning the air filter the
engine still will not idle, adjust the idle speed screw as follows:
WARNING:
The unit will still run during idle
speed adjustments. Wear protective clothing and
observe all safety instructions to prevent serious
personal injury.
1. Start the engine and let it run for about 2-3 minutes at a high
speed (full throttle) to warm up. Refer to the
Starting/Stopping Instructions.
NOTE: Ensure the tines are not in contact with the ground when
adjusting the idle.
2. Release the throttle control and let the engine idle. If the engine stops, insert a small phillips
screwdriver into the hole in the muffler cover (Fig. 18). Turn the idle speed screw clockwise 1/8 of a
turn at a time (as needed) until the engine idles smoothly.
NOTE: The tines should not rotate during engine idle.
3. If the tines rotate 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 screw should solve most
engine problems. If not and all 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.
Fig. 9
Fig. 14
Fig. 15
Fig. 16
Slots Engine
Spark Muffler
Arrestor
Hood
Spark Arrestor
Screw
Tabs Screen
Fig. 17
Idle Speed Screw
Fig. 18
5