• 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 753-05784 or Champion® RDZ4H spark plug. The
correct air gap is 0.025 in. (0.635 mm). Remove the plug after every 40 hours of operation
and check its condition.
1. Stop the engine and allow it to cool. Remove the two (2) screws on back of the engine
cover and the one on the front of the engine cover with a Flat-head or T-25 Torx
screwdriver (Fig. 34).
2. Grasp the plug wire firmly and pull the cap from the spark plug.
WARNING:
Do not sand blast, scrape
or clean electrodes. Grit in the engine
could damage the cylinder.
3. Clean dirt from around the spark plug. Remove the
spark plug from the cylinder head by turning a 5/8
in. socket counterclockwise.
3. Replace cracked, fouled or dirty spark plug. Set the
air gap at 0.025 in. (0.635 mm) using a feeler gauge
(Fig. 39).
4. 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 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 diverter to the muffler (Fig. 40).
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 screw.
CLEANING
WARNING:
To avoid serious personal
injury, always turn the unit off and allow it
to cool before cleaning or servicing it.
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.
MAINTENANCE AND REPAIR INSTRUCTIONS
0.025 in.
(0.635 mm.)
Fig. 39
Muffler
Spark Arrestor
Screen
Diverter
T-25
Screw
Slot
T-20 Screw
Fig. 40
ELECTRIC STARTER AND POWER START BIT™ FEATURES
This unit is designed to be started with an optional electric starter or Power Start Bit™ that
are sold separately. If choosing to start the unit using one of these features or have
questions please contact your local retailer or call 1-800-828-5500 U.S, (1-800-668-1238
Canada), for more information and purchasing. You may also go to www.troybilt.com or
www.troybilt.ca.
Electric Start Feature
7