Husqvarna 331RB Workshop Manual page 25

10. Use the pliers or a screwdriver to align the spring
with the hole in the spark plug cap.
CAUTION: Be very careful to prevent
damage to the spark plug cap. A damaged
spark plug cap can cause an electrical
shock.
7.7.5 To disassemble the ignition system
1. Pull up the knob and remove the shaft.
2. Remove the spark plug cap.
3. Remove the spark plug.
4. Put a piston stop in the spark plug hole to prevent
movement of the piston.
1281 - 001 -
5. Disconnect the throttle wire from the carburetor.
6. Disconnect the cables.
Repair instructions - 25