Servicing The Spark Plug - Husqvarna ST 121E Operator's Manual

Servicing the Spark Plug

Use a NGK BPR6ES, Champion RN9YC, or BOSCH
WR6DC spark plug or equivalent.
1. Move snow thrower to a level surface.
2. Run snow thrower until all fuel has been depleted.
3. Wait until engine is cool.
4. Rotate the discharge chute so that it faces forward.
5. Remove the discharge chute by removing the three
carriage bolts and three flange nuts (Figure 26).
3
2
Figure 26
1. Discharge chute
2. Carriage bolts
6. Remove two screws in plenum that hold top cover
(Figure 27).
7. Remove the oil fill cap.
1
4
Figure 27
1. Screw
2. Plenum
MAINTENANCE
1
3
2
3. Flange nuts
2
3
3. Oil fill cap
4. Top cover
8. Unsnap top cover by firmly pulling upwards at the
rear section of the cover disengaging the three clips
(Figure 28).
9. Shift top cover until fuel tank is clear of the rear upper
cover and set top cover to the side of the unit.
10. Temporarily reinstall oil fill cap to prevent foreign object
from entering the engine.
11. Remove 2 screws in the side cover and rear covers
on both sides.
1
3
1. Top cover
2. Clips
12. Unplug electrical wires on back of ignition switch
(Figure 29).
13. Pull tube off the back of the primer bulb.
1. Electrical wires
2. Ignition switch
14. Lift rear upper cover and lay it to the side of the unit.
IMPORTANT: The recoil rope will still be attached to the
upper cover.
14
2
3
4
Figure 28
3. Screw
4. Rear upper cover
4
2
2
1
Figure 29
3. Tube
4. Primer bulb
3
4
3