MTD YARD-MAN YM21CS - Maintenance, Troubleshooting, and Specs; Replacing the Spark Plug; Cleaning and Storage; Troubleshooting Engine Issues

5
MAINTENANCE AND REPAIR INSTRUCTIONS
SPECIFICATIONS
CLEANING AND STORAGE
CLEANING
U
se a small brush to clean off the outside of the unit. Do not use strong detergents. Household cleaners that contain
a
romatic oils such as pine and lemon, and solvents such as kerosene, can damage plastic housing or handle. Wipe off
a
ny moisture with a soft cloth.
S
TORAGE
•
Never store a fueled unit where fumes may reach an open flame or spark.
•
Allow the engine to cool before storing.
• Store the unit locked up to prevent unauthorized use or damage.
• Store the unit in a dry, well-ventilated area.
• Store the unit out of the reach of children.
S
hort Term Storage (1-2 weeks)
1
. Store the unit in a horizontal position. If this is not possible, store the unit vertically with the engine at the top.
L
ong-term Storage
1
. Remove the fuel cap, tip the unit and drain the fuel into an approved container.
N
OTE: Do not use gasoline that has been stored for more than 30 days. Dispose of old gasoline in accordance with
f
ederal, state and 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 5 drops of any high quality motor oil or 2-cycle 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 it for any loose or damaged parts. Repair or replace damaged parts and
tighten loose screws, nuts or bolts. The unit is ready for storage.
WARNING:
To avoid serious personal injury, always turn the unit off and allow it to cool before you
clean or service it.
C
AUSE
A
CTION
The fuel is old (over 30 days) and/or improperly mixed Drain the fuel tank and add fresh, properly mixed fuel
F
ouled spark plug
R
eplace or clean the spark plug
The fuel is old (over 30 days) and/or improperly mixed Drain the fuel tank and add fresh, properly mixed fuel
C
utting head bound with grass
S
top the engine and clean the cutting head
Dirty air filter Clean or replace the air filter
Empty fuel tank Fill fuel tank with properly mixed fuel
T
he primer bulb wasn't pressed enough
P
ress the primer bulb 10 times or until fuel is visible
E
ngine is flooded
With the choke lever in position 3, squeeze the trigger
and pull the starter rope
T
he fuel is old (over 30 days) and/or improperly mixed
D
rain the fuel tank and add fresh, properly mixed fuel
Fouled spark plug Replace or clean the spark plug
C
utting head bound with grass
S
top the engine and clean cutting head
C
utting head out of line
R
efill with new line
I
nner reel bound up
R
ewind the inner reel
Cutting head dirty Clean inner reel and outer spool
Line welded Disassemble, remove the welded section and rewind
L
ine twisted when refilled
D
isassemble and rewind the line
N
ot enough line is exposed
P
ush the bump knob and pull out line until 4 inches (102 mm)
o
f line is outside of the cutting head
Oil, cleaner or lubricant in cutting head Clean and thoroughly dry the cutting head
Air filter is plugged Replace or clean the air filter
The fuel is old (over 30 days) and/or improperly mixed Drain the fuel tank and add fresh, properly mixed fuel
I
mproper idle speed
A
djust the idle speed
T
ROUBLESHOOTING
ENGINE WILL NOT START
E
NGINE WILL NOT IDLE
ENGINE WILL NOT ACCELERATE
IF FURTHER ASSISTANCE IS REQUIRED, CONTACT AN AUTHORIZED SERVICE DEALER.
E
NGINE LACKS POWER OR STALLS
CUTTING LINE ADVANCES UNCONTROLLABLY
C
UTTING HEAD WILL NOT ADVANCE LINE
Engine Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air-Cooled, 2-Cycle
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.10 in. (2.6 cm)
Displacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 cc
Operating RPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,300 + rpm
Idle Speed RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,800 - 3,400 rpm
Spark Plug Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 in. (0.635 mm)
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel/Oil Mixture
Fuel/Oil Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40:1
Fuel Tank Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 fl. oz. (296 ml)
Approximate Unit Weight (No fuel, with cutting attachment, shield and D-handle)10 - 11 lbs. (4.5 - 5 kg)
Cutting Mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bump Head™
Line Spool Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 in. (76.2 mm)
Trimming Line Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.095 in. (2.41 mm)
Cutting Path Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 in. (43.18 cm)
* All specifications are based on the latest product information available at the time of printing. We
reserve the right to make changes at any time without notice.
REPLACING THE SPARK PLUG
Use replacement #753-06193, a Champion RDJ7J spark plug, or equivalent.
The correct air gap is 0.025 inch (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 and pull
it from the spark plug.
2.
Clean around the spark plug. Remove the spark plug from the cylinder head
by turning a 5/8-inch socket counterclockwise.
3. Replace a cracked, fouled or dirty spark plug. Set the air gap at 0.025 in.
(0.635 mm) using a feeler gauge (Fig. 25).
4. Install a correctly-gapped spark plug in the cylinder head. Tighten by turning the 5/8-inch 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.
WARNING:
Do not sand blast, scrape or clean electrodes. Grit in the engine could
damage the cylinder.
Fig. 25
0
.025 in.
(0.635 mm.)