DO NOT use a cutting blade that shows signs of excessive wear
or damage.
Standard Blade Wear Limit
1. Inspect the blade (Figure 21) frequently for signs of
excessive wear or damage:
• (A) New blade
• (B) Wear limit (notch starts)
• (C) Dangerous condition! Do not use on the mower!
Replace with a new blade.
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Ninja Blade Wear Limit
1. Inspect the blade (Figure 22) frequently for signs of
excessive wear or damage:
• (A) New blade
• (B) Wear limit (cracks or notches begin to appear on
tip)
• (C) Dangerous condition! Do not use on the mower!
Replace with a new blade.
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Blade Sharpening
1. Disconnect the spark plug wire and secure the end away
from the plug.
2. Tilt the mower up on its rear wheels. Do not tilt the mower
with the spark plug or carburetor down.
NOTICE
Drain the fuel tank before tipping the mower. DO NOT tip the
machine with the carburetor or spark plug down. Oil from the
crankcase will saturate the air filter and cause the engine to
be hard to start or not start at all. If contamination does occur,
the air filter will have to be replaced.
3. Remove the blade (B, Figure 23).
4. Sharpen the blade on a grinding wheel at an angle of 22 to
28 degrees (B, Figure 24). DO NOT sharpen the blade
beyond the original cutting edge (A).
5. Check blade for balance. If necessary, correct balance by
grinding heavy end of blade.
6. Reinstall blade (B, Figure 23). Note the correct assembly
order:
• (A) Blade hub
• (B) Blade
• (C) Blade flange (facing up)
• (D) Cone washer (concave side up)
• (E) Capscrew
7. Check torque of blade retaining cap screw. Recommended
torque: 40 lb-ft (54 Nm).
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