Craftsman 316.794611 Operator's Manual page 16

MAINTAINING THE SPARK PLUG
1. Stop the engine and allow it to cool.
2. Open the spark plug cover (Fig. 16). Grasp the spark plug boot
firmly and pull it from the spark plug.
3. Clean around the spark plug. Remove the spark plug from the
cylinder head with a 5/8-inch socket, turning counterclockwise.
WARNING:
Do not sand blast, scrape or clean spark plug
electrodes. Grit in the engine could damage the cylinder.
4. Inspect the spark plug. If the spark plug is cracked, fouled or
dirty, replace it with replacement part #753-05784, a Champion
RDZ4H or an equivalent spark plug.
5. Use a feeler gauge to set the air gap at 0.025 in. (0.635 mm)
(Fig. 17).
6. Install the spark plug in the cylinder head. Tighten the spark plug
with a 5/8-inch socket, turning it clockwise until snug.
NOTE: If using a torque wrench, torque to:
110-120 in.•lb. (12.3-13.5 N•m). Do not over tighten.
7. Reattach the spark plug boot. Close the spark plug cover.
Spark Plug Cover
0.025 in.
(0.635 mm)
16
Fig. 16
Fig. 17