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6.
Pull the starter rope 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 while looking in the
spark plug hole (Fig. 37).
•
Both rocker arms move freely, and both valves are closed.
If these statements are not true, repeat this step.
7.
Slide the feeler gauge between the rocker arm and the
valve return spring. Measure the clearance between the
valve stem and rocker arm (Fig. 38). 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 38 and 39.
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. 39).
•
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. 40).
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. 40).
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. 41).
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
trimmer 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.
7
MAINTENANCE AND REPAIR INSTRUCTIONS
WARNING:
To avoid serious personal injury, always turn the unit off and allow it to cool
before you clean or service it.
WARNING:
Do not sand blast, scrape or clean electrodes. Grit in the engine could
damage the cylinder.
Valve Stem
Fig. 39
Adjusting Nut
Feeler
Gauge
Rocker Arm
0.003–0.006 in.
(0.076–0.152 mm)
Muffler
Fig. 41
Slot
Fig. 40
0.025 in.
(0.635 mm.)
Spark Arrestor
Screen
Diverter
T-25
Screw
T-20 Screw
ELECTRIC START FEATURE
This unit is designed to be started with an optional electric starter. If choosing to start the unit using the electric
start feature please refer to the Electric Starter operator’s manual for correct starting procedure. If you have any
questions please call 1-800-828-5500
.
Electric Start Feature