MTD MP426CS - Manual (Page 19)

19
SECTION 7: MAINTENANCE AND REPAIR INSTRUCTIONS
Replacing the Spark Plug
Use a Champion RDZ19H spark plug (or equivalent). The
correct air gap is 0.025 inch (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 it from the spark plug.
2. Clean 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.
See Figure 42.
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. Tighten by turning the 5/8 inch 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.
0.025 in.
(0.655 mm)
Figure 42
Muffler Spark Arrestor Screen
Spark Arrestor Cover
Screw Tab
Slot
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. See Figure 43.
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.
Figure 43