Replacing The Spark Plug; Spark Arrestor - Troy-Bilt TB490BC Operator's Manual

REPLACING THE SPARK PLUG
Use only Champion I,ZI_)Z19H spark plug or equivalent. I he
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 f'rom the spark plug.
2. Clean dirt f'rom 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 ram.) using a reeler'gauge (Fig. 57).
s7
4. Install a correctly-gapped spark plug in the cylinder
head. lurn the 5/8 in. socket clockwise until snug.
If using a torque wrench torque to:
110-120 in,.Ib, (12.3-13.5 N.m)
Do not over tighten.
SPARK ARRESTOR MAINTENANCE
1. I;_emovethe mL_ff]ercover. See RockerArm Cfearance.
2. With a flat blade screwdriver or Iorx 1-20 bit,
remove the screw attaching the spark arrestor cover
to the muffler (Fig. 58).
,
4.
6.
6.
I_ull the tab on the spark arrestor cover out of the
muffler. Remove the spark arrestor cover.
Remove the spark arrestor screen f'rom the spark
arrestor cover.
Clean the spark arrestor screen with a wire brush or
replace it.
Reinstall the spark arrestor screen, spark arrestor
cover and screw.