Troubleshooting; Specifications - Yard Machines YM121 Operator's Manual

MAINTENANCE AND REPAIR INSTRUCTIONS
REPLACING THE SPARK PLUG
Use a Champion RDJ7Y spark plug (or equivalent). The correct air gap is 0.025 in. (0.635 mm). Remove
the plug after every 25 hours of operation to check its condition.
1. Stop the engine and allow it to cool. Grasp the plug wire firmly 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.
NOTE: Replace a cracked, fouled or dirty spark plug.
3. Set the air gap at 0.025 in. (0.635 mm) using a feeler gauge
(Fig. 19).
WARNING: Do not sand blast, scrape or clean
electrodes. Grit in the engine could damage the
cylinder.
4. Install a correctly gapped spark plug in the cylinder head.
Tighten by turning 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 THE UNIT
WARNING: To avoid serious personal injury, always turn your unit off and allow it to
cool before you clean or service it.
• Use a small brush to clean off the outside of the unit and to keep the air vents free of obstructions.
• Do not use strong detergents or petroleum based cleaners, like kerosene. Some household cleaners
contain aromatic oils such as pine and lemon that can damage the plastic housings or handles. Wipe
off any moisture with a soft cloth.
STORAGE
• Never store a fueled unit where fumes may reach an open flame or spark.
• Allow the engine to cool before storing.
• Store the unit in a locked up area 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
If you plan to store the unit for an extended time:
1. Drain all fuel from the fuel tank into a container. Do not use fuel that has been stored for more than
60 days. Dispose of the old fuel in accordance to local regulations.
2. Start the engine and allow it to run until it stalls. This ensures
that all fuel has been drained from the carburetor.
3. Allow the engine to cool. Remove the spark plug and put 1
oz. (30 ml) 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 unit 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 fuel tank before transporting.
• Tighten fuel cap before transporting.
MOVING THE UNIT
1. Allow the unit to cool before moving.
2. Loosen the knobs on the handlebar.
3. Fold the handlebars down as shown (Fig. 20).
4. Either carry the unit by the shaft tube grip or grasp the center
of the handlebar to use it as a carrying handle (Fig. 21).
5. After the unit has been moved, reposition the handlebars and
continue operation.
6
0.025 in.
(0.635 mm)
Fig. 19
Handlebar
Engine Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air-Cooled, 2-Cycle
Knobs
Displacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 cc
Idle Speed RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,600-3,600 rpm
Operating RPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,800+ rpm
Fig. 20
Clutch Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Centrifugal
Shaft Tube Ignition Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electronic
Grip
On/Off Stop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rocker Switch
Spark Plug Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 inch (0.635 mm)
Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel/Oil Mixture
Fuel/Oil Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40:1
Carburetor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diaphragm, All-Position
Starter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Auto Rewind
Muffler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Baffled with Guard
Throttle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spring Return
Fig. 21
Fuel Tank Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 ounces (415 ml)
Drive Shaft Tube. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steel Tube
Throttle Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Finger-Tip Trigger
Cultivating Path Width (Maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 inches (22.86 cm)
Cultivating Depth (Maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 inches (15.24 cm)
Approximate Weight (no fuel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 lb. (12 kg)

TROUBLESHOOTING

ENGINE WILL NOT START
CAUSE
On/Off control in the OFF position
Empty fuel tank
Primer bulb wasn't pressed enough
Engine is flooded
Old or improperly mixed fuel
Fouled spark plug
Plugged spark arrestor
ENGINE WILL NOT IDLE
CAUSE
Air filter is plugged
Old or improperly mixed fuel
Improper carburetor adjustment
ENGINE WILL NOT ACCELERATE
CAUSE
Old or improperly mixed fuel
Dirty air filter
Plugged spark arrestor
ENGINE LACKS POWER OR STALLS WHEN CULTIVATING
CAUSE
Old or improperly mixed fuel
Fouled spark plug
Plugged spark arrestor
If further assistance is required, contact your authorized service dealer.

SPECIFICATIONS

ENGINE*
DRIVE SHAFT & CUTTING ATTACHMENT*
ACTION
Turn On/Off control to ON
Fill fuel tank with properly mixed fuel
Press primer bulb fully and slowly 10 times
Place choke lever into position 3, squeeze the
throttle trigger and pull the starter rope
Drain gas tank and add fresh fuel mixture
Replace or clean the spark plug
Clean or replace spark arrestor
ACTION
Replace or clean the air filter
Drain gas tank and add fresh fuel mixture
Adjust according to the Carburetor Adjustments
section or take to an authorized service dealer for
an adjustment
ACTION
Drain gas tank and add fresh fuel mixture
Clean or replace the air filter
Clean or replace spark arrestor
ACTION
Drain gas tank and add fresh fuel mixture
Replace or clean the spark plug
Clean or replace spark arrestor