Replacing Spark Plug; Spark Arrestor Maintenance - Troy-Bilt TB425CS Operator's Manual

MAINTENANCE AND REPAIR INSTRUCTIONS
REPLACING THE SPARK PLUG
Use only Champion RDZ19H spark plug or equivalent. The
correct air gap is 0.025 in. (0.655 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 the cap from the spark plug.
2. 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. (0.655 mm.) using a feeler gauge (Fig. 47).
0.025 in.
(0.655 mm.)
CAUTION: Do not sand blast, scrape, or
clean electrodes. Grit in the engine could
damage the cylinder.
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.
20
Fig. 47

SPARK ARRESTOR MAINTENANCE

1. Remove the muffler cover. See Rocker Arm Clearance.
2. With a flat blade screwdriver or Torx T-20 bit,
remove the screw attaching the spark arrestor cover
to the muffler (Fig. 48).
Muffler
Slot
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.
Spark Arrestor Screen
Tab
Spark Arrestor Cover
Fig. 48
Screw