Idiomas disponibles
Idiomas disponibles
AIR FILTER MAINTENANCE
WARNING:
To avoid serious personal injury, always turn the
unit off and allow it to cool before cleaning or maintaining it.
Cleaning the Air Filter
Failure to maintain the air fi lter will VOID the warranty.
1. To open the air fi lter cover, push
the tab on the left side of the cover
inward and pull the air fi lter cover
slightly out and to the right (Fig. 18).
2. Remove the air fi lter (Fig. 18).
3. Wash the fi lter in detergent and
water. Making sure to rinse the fi lter
thoroughly and allow it to dry.
4. Lightly coat the fi lter with clean SAE
30 motor oil.
5. Squeeze the fi lter to spread and remove excess oil.
6. Replace the fi lter.
NOTE:
Operating the unit without the air fi lter will VOID the warranty.
7. To reinstall the air fi lter cover, position the hooks on the right side of the
air fi lter cover into the slots at the right side of the back plate (Fig. 18).
8. Swing the cover to the left and press closed so the air fi lter cover tab
snaps into the slot on the back plate (Fig. 18).
IDLE SPEED ADJUSTMENT
The idle speed of the engine is adjustable. An idle adjustment screw is
between the air fi lter cover and the engine starter housing (Fig. 19).
NOTE:
Careless adjustments can seriously damage to the unit. A Sears or
other qualifi ed service dealer should make carburetor adjustments.
Check Fuel
Old fuel is usually the reason for poor unit performance. Drain and refi ll the
tank with fresh fuel prior to making any adjustments. Refer to Oil and Fuel
Information.
Clean Air Filter
The condition of the air fi lter is important to the operation of the unit. A dirty
air fi lter will restrict air fl ow. This is often mistaken for an out of adjustment
carburetor. Check the condition of the air fi lter prior to adjusting the idle
speed screw. Refer to Air Filter Maintenance.
Adjust Idle Speed Screw
If, after checking the fuel and cleaning the air fi lter, the engine still will not
idle, adjust the idle speed screw as follows:
1. Start the engine and warm up according to the Starting/Stopping
Instructions.
2. Release the trigger and let the engine idle. If the engine stops, insert a
small phillips screwdriver in between the Air Filter Cover and the Engine
Cover (Fig. 19). Turn the idle speed
screw 1/8 of a turn clockwise at a
time until the engine idles smoothly.
Checking the fuel, cleaning the air fi lter,
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
•
take the unit to a Sears or other qualifi ed service dealer.
ROCKER ARM CLEARANCE
WARNING:
To avoid serious personal injury, always turn the
unit off and allow it to cool before cleaning or maintaining it.
This requires disassembly of the engine. If you feel unsure or unqualifi ed to
perform this, take the unit to a Sears or
other qualifi ed service dealer.
The engine must be cold when
•
checking or adjusting the rocker arm
clearance.
This task should be performed
•
inside, in a clean, dust free area.
1. Remove the 8 engine cover screws
with the appropriate tool (Fig. 20),
then remove the cover.
MAINTENANCE INSTRUCTIONS
Slot
Tab
Air Filter
Air Filter Cover
Fig. 18
Idle Adjustment
Screw
Fig. 19
Screws
Screws
Fig. 20
NOTE:
Make sure to store the screws
so that they can be reinstalled
into their original holes.
2. Disconnect the spark plug wire.
3. Clean dirt from around the spark
plug and rocker arm cover.
Remove the spark plug from the
cylinder by turning a 5/8 in. socket
counterclockwise.
4. Remove the screw holding the rocker
arm cover with the appropriate tool
(Fig. 21). Remove the rocker arm
cover and gasket.
5. Turn the fl ywheel slowly to bring the
piston to the top of its travel (known
as top dead center). Check that:
The piston is at the top of its travel
•
by looking in the spark plug hole
(Fig. 21)
Both rocker arms move freely, and
•
both valves are closed.
If these statements are not true, repeat this step.
6. Slide the feeler gauge between the rocker arm and the valve return
spring. Measure the clearance between the valve stem and rocker arm
(Fig. 22). Measure both the intake and exhaust valves.
The recommended clearance for both intake and exhaust is .003 – .006 in.
(.076 – 0.152 mm). Use a standard automotive .005 in. (0.127 mm) feeler
gauge. The feeler gauge should slide between the rocker arm and valve stem
with a slight amount of resistance, without binding. See Figures 22.
7. If the clearance is not within specifi cation:
a. Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut driver (Fig. 22).
To increase clearance, turn the adjusting nut counterclockwise.
•
To decrease clearance, turn the adjusting nut clockwise.
•
b. Recheck both clearances, and adjust as necessary.
8. Reinstall the rocker arm cover using a new gasket (Fig. 21). Torque the
screw to: 20–30 in•lb (2.2–3.4 N•m).
9. Check the spark plug and reinstall. See Replacing the Spark Plug.
10. Reinstall the spark plug wire.
11. Reinstall the engine cover. Check alignment of the cover before
tightening the screws. Tighten screws.
NOTE:
Make sure that the screws are reinstalled into their original holes
(Fig. 20).
REPLACING THE SPARK PLUG
Use a replacement part number 753-05784 or Champion spark plug
#RDZ4H. The correct spark gap is 0.025 in. (0.635 mm).
1. Stop the engine and allow it to cool.
2. Open the spark plug cover (Fig. 23).
3. Grasp the plug wire fi rmly and pull the cap from the spark plug.
4. 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 spark plug
electrodes. Grit in the engine could damage the cylinder.
5. Replace cracked, fouled or dirty
spark plug. Set the spark gap at
0.025 in. (0.635 mm) using a feeler
gauge (Fig. 24).
6. Install a correctly-gapped spark plug
in the cylinder head. Turn the 5/8 in.
socket clockwise until snug.
7. Reinstall the spark plug cover.
If using a torque wrench, torque to:
110-120 in.•lb. (12.3-13.5 N•m)
Do not over tighten.
Rocker
Arm
Cover
Screw
Spark
Plug
Hole
Fig. 21
Adjustment Nut
Rocker Arm
0.003–0.006 in.
(0.076–0.152 mm)
Valve
Feeler Gauge
Stem
Fig. 22
Fig. 23
0.025 in.
(0.635 mm)
Fig. 24
7
