Exmark Metro 21 - Manual (Page 22)

18
Sharpening the Blade
File the top side of the blade to maintain its original
cutting angle (Fig. 19A) and inner cutting edge radius
(Fig. 19B). The blade will remain balanced if you remove
the same amount of material from both cutting edges.
153
1
mĆ4783
2
A B
Figure 19
1. Sharpen at this angle only 2. Maintain the original
radius here
Balancing the Blade
1. Check the balance of the blade by placing the center
hole of the blade over a nail or screwdriver shank
clamped horizontally in a vise (Fig. 20).
1007
Figure 20
Note: You can also check the balance using a
commercially manufactured blade balancer.
2. If either end of the blade rotates downward, file that
end (not the cutting edge or the end near the cutting
edge). The blade is properly balanced when neither
end drops.
Installing the Blade
1. Install a sharp, balanced Exmark blade, the
accelerator, the lock washer, and the blade bolt. The
sail of the blade must point toward the top of the lawn
mower housing for proper installation. Torque the
blade bolt to 50 ft-lb (68 N
m).
Operating the lawn mower without the
accelerator in place can cause the blade to flex,
bend, or break, resulting in serious injury or
death to the operator or bystanders.
Do not operate the lawn mower without the
accelerator.
Warning
2. Return the lawn mower to its upright position.
3. Connect the wire to the spark plug.
Cleaning under the Belt Cover
Self-propel Model only
Keep the area under the belt cover free of debris.
1. Stop the engine and wait for all moving parts to stop.
2. Disconnect the wire from the spark plug (Fig. 6).
3. Remove the bolts that secure the belt cover to the lawn
mower housing (Fig. 21).
m-224
1
Figure 21
1. Belt cover
4. Lift off the cover and brush out all the debris around
the belt area.
5. Install the belt cover.
6. Connect the wire to the spark plug.