Husqvarna ST 151 Operator's Manual page 15

15. Disconnect the spark plug wire from the spark plug
(Figure 31).
16. Clean around the spark plug.
17. Remove the spark plug from the cylinder head.
1
Figure 31
1. Spark plug wire
IMPORTANT: Replace a cracked, fouled, or dirty spark
plug. Do not clean the electrodes because grit entering
the cylinder can damage the engine.
18. Set the gap on the plug to 0.030 inch (0.76 mm)
(Figure 32).
Figure 32
MAINTENANCE
0.030 inch
(0.76 mm)
19. Install the spark plug and torque it to 20–22 ft-lb
(27–30 N-m).
20. Connect the spark plug wire to the spark plug
(Figure 31).
21. Reattach primer bulb tube to primer bulb and electri-
cal wires on back ignition switch of rear upper cover
(Figure 30).
22. Set rear upper cover in place so the two screw holes
line up with the rear lower cover and side covers
(Figure 33).
1. Rear upper cover
2. Screw
23. Reattach two screws through the rear covers and into
the clip on the side cover (Figure 28).
24. Remove top oil fill cap.
25. Set top cover in place and snap three top cover clips
into the rear upper cover (Figure 29).
26. Reinstall top oil fill cap.
27. Reinstall two screws in the side covers that attach to
the clips on the top cover.
28. Reinstall two screws in the plenum that attach to the
top cover (Figure 28).
29. Reinstall discharge chute with the hardware removed
in step 5.
15
1
2
Figure 33