Craftsman 316.77237 - Manual (Page 12)

Fig. 32
INTAKE
Spark Plug Hole
Feeler Gauge
Rocker Arms Adjusting
Screws
EXHAUST
between the valve stem and rocker arm (Fig. 32). 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 32 and 33.
8. If the clearance is not within specification:
a. Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut
driver (Fig. 32).
• To increase clearance, turn the adjusting nut counterclockwise.
• To decrease clearance, turn the adjusting nut clockwise.
b. Recheck both clearances, and adjust as necessary.
9. Reinstall the rocker arm cover using a new gasket. Torque the
screw to 20–30 in•lb (2.2–3.4 N•m).
10. Check the spark plug and reinstall. See Replacing the Spark Plug.
11. Replace the spark plug wire.
12. Reinstall the engine cover. Check alignment of the cover before
tightening the screws. Tighten screws.
REPLACING THE SPARK PLUG
Use a replacement part number 753-05255 spark plug. The correct
air gap is 0.025 in. (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. Remove the six (6) screws
on the back of the engine cover with a Flat-head or T-25 Torx
screwdriver (Fig. 30).
2. Grasp the plug wire firmly and pull the cap from the spark plug.
3. Clean dirt from around the spark plug. Remove the spark plug from
the cylinder head by turning a 5/8 in. socket counterclockwise.
4. Replace cracked, fouled or dirty spark plug. Set the air gap at
0.025 in. (0.635 mm) using a feeler gauge (Fig. 34).
5. Install a correctly-gapped spark plug
in the cylinder head. Turn 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.
SPARK ARRESTOR MAINTENANCE
1.
Remove the rear engine cover. See
Rocker Arm Clearance.
2. With a flat blade screwdriver or Torx
T-20 bit and a T-25 bit, remove the
screws attaching the
spark arrestor cover
to the muffler (Fig. 35).
3. Pull the tab on the
spark arrestor cover
out of the muffler.
Remove the spark
arrestor cover.
4. Remove the spark
arrestor screen from
the spark arrestor
cover.
5. Clean the spark
arrestor screen with a
wire brush or replace it.
6. Reinstall the spark
arrestor screen, spark
arrestor cover and
screws.
CLEANING
Use a small brush to clean off the outside of the unit. Do not use
strong detergents. Household cleaners that contain aromatic oils
such as pine and lemon, and solvents such as kerosene, can damage
plastic housing or handle. Wipe off any moisture with a soft cloth.
STORAGE
• Never store the unit with fuel in the tank where fumes may reach
an open flame or spark.
• Allow the engine to cool before storing.
• Lock up the unit 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
1.
Drain all gasoline from the gas tank into a container. Do not use
gas that has been stored for more than 60 days. Dispose of the old
gasoline in accordance to Federal, State, and Local regulations.
2. Start the engine and allow it to run until it stalls. This ensures
that all gasoline has been drained from the carburetor.
3. Allow the engine to cool. Remove the spark plug and put 5
drops 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 edger after storage.
4. Change the oil, referring to Changing the Oil. Dispose of the old
oil in accordance to Federal, State and Local regulations.
5. 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 gas tank before transporting.
• Tighten gas cap before transporting.
Fig. 33
Adjusting Nut
Feeler Gauge
Rocker Arm
.003–.006 in.
(.076–.152 mm)
Intake
Valve Stem
Exhaust
Valve Stem
Fig. 34
0.025 in.
(0.635 mm)
WARNING: Do not sand blast, scrape or clean
electrodes. Grit in the engine could damage the cylinder.
WARNING: To avoid serious personal injury, always turn
your unit off and allow it to cool before you clean or service it.
Fig. 35
Muffler
Spark Arrestor
Screen
T-30 Screw
T-25
Screw
Slot
Spark Arrestor
Cover
MAINTENANCE AND REPAIR INSTRUCTIONS
12