15
Note: The running time and the roughness of the driveway
or the sidewalk determines the wear rate of the rotor
blades.
Removing the Old Blade
Note: You will need a No. T27 torx driver to complete
this procedure.
1. Remove the 4 torx screws and the 4 locknuts that
secure the outer edges of the rotor blade to the rotor
shaft assembly (Fig. 19).
1
2
3
4
4
5
6
7
8
680
Figure 19
1.
Rotor blade
2.
Rotor half
3.
Torx screw
4.
Locknut
5.
Hex-head screw
6.
Spacer
7.
Auger shaft assembly
8.
Hex-head screw
2. Remove the 2 hex-head screws, 2 spacers, and 2
locknuts that secure the center of the blade to the rotor
halves (Fig. 19).
3. Loosen the hex-head screw that secures the rotor
halves to the auger shaft assembly (Fig. 19).
4. Slide the blade out from between the rotor halves
(Fig. 19).
Installing a New Blade
1. Examine a new rotor blade edge for the difference in
layer thickness (Fig. 20). Some rotor blades have a
part number on the thick side of the blade.
3
1
681
2
Figure 20
1.
Thick layer
2.
Wear indicator hole
3.
Thin layer
Install the rotor blades with the thick layer on the
inside of the curve. (Fig. 20). If you do not install the
blades properly, the blades may be out of balance and
cause the snowthrower to “hop” or “bounce.”
2. Insert the new rotor blade between the rotor halves.
3. Secure the rotor blade to the rotor halves with 2
hex-head screws, 2 spacers, and 2 locknuts,
positioning the bolt heads on the thick side of the
blade (Fig. 19).
4. Curve the rotor blade and secure it with the remaining
torx screws and locknuts, positioning the screw heads
on the thick side of the blade (Fig. 19).
5. Tighten all screws and locknuts securely.
Replacing the Spark Plug
Before each season, check the spark plug. If the electrodes
in the center of the plug are dark or have deteriorated,
install a new NGK BPMR4A spark plug or equivalent.
1. Remove the 3 mounting screws that secure the control
panel to the housing (Fig. 15).
2. Remove the ignition key and lift off the panel,
allowing it to hang on the recoil rope.
3. Disconnect the wire from the spark plug and remove
the spark plug (Fig. 16).
4. Examine the spark plug and replace it if it is cracked,
fouled, or dirty.
Important
Do not sandblast, scrape, or clean the spark
plug. Dirt may fall into the cylinder and cause engine
damage.
5. Set the spark plug gap (Fig. 21) between the electrodes
to 0.032 inches (0.81 mm).
