Sharpening the Blade
File the top side of the blade to maintain its original cutting angle (Fig. 25A) and inner cutting edge radius (Fig. 25B). The blade will remain balanced if you remove the same amount of material from both cutting edges.
A | 1 | B | 2 |
|
| 153 | |
|
| Figure 25 | |
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. 26).
1007
Figure 26
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.
3.Return the lawn mower to its upright position.
4.Connect the wire to the spark plug.
Cleaning the Blade Brake Clutch Shield
Clean the BBC (blade brake clutch) shield at the end of each mowing season to ensure the best performance and to prevent parts from degrading. Clean the BBC shield when you sharpen the blade because you need to remove the blade in order to remove the BBC shield.
1.Stop the engine and wait for all moving parts to stop.
2.Disconnect the wire from the spark plug (Fig. 9).
3.Drain the gasoline from the fuel tank; refer to Emptying the Fuel Tank and Cleaning the Fuel Filter on page 19.
4.Tip the lawn mower onto its right side (air filter up).
Warning
Tipping the lawn mower may cause the fuel to leak from the carburetor or the fuel tank. Gasoline is extremely flammable, highly explosive, and, under certain conditions, can cause personal injury or property damage.
Avoid fuel spills by emptying the fuel tank as directed; never siphon.
5.Remove the two blade nuts, the
Installing the Blade
1 
2
1.Install a sharp, balanced Exmark blade, the blade accelerator, the
2.Torque the blade nuts to 15 to 27
Warning
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.
3
|
| Figure 27 |
1. | Tabs and nuts | 3. Tab and bolt |
2. | BBC shield |
|
|
|
|
6.Loosen the tabs that secure the BBC shield to the deck by loosening the nuts or the bolts on the tabs (Fig. 27). Rotate the tabs 180 to move them out of the way.
7.Remove the BBC shield and brush or blow all the debris from under the shield and around the BBC system.
18
