Section 4 - REPAIR & ADJUSTMENTS
WARNING
Before attempting any adjustments or repairs, STOP the engine, remove the spark plug wire from the spark plug and secure wire away from plug. Wear heavy leather gloves when handling or working around cutting blades. Blades are extremely sharp and can cause severe injury.
4.1MOWER BLADE REPAIR/REPLACEMENT 4.1.1. STANDARD BLADE WEAR LIMIT
1.Inspect blade frequently for signs of excessive wear or damage. See Figure 4.1.
NEW BLADE
WEAR LIMIT (NOTCH STARTS)
DANGEROUS
CONDITION !
DO NOT USE ON
MOWER !
REPLACE WITH NEW
BLADE.
FIGURE 4.1
4.1.1A. NINJA BLADE WEAR LIMIT
1A. Inspect blade frequently for signs of excessive wear or damage. See Figure 4.1A.
NEW BLADE | WEAR LIMIT. | |
CRACKS OR | ||
| ||
| NOTCHES | |
| BEGIN TO | |
| APPEAR ON TIP |
DANGEROUS !
DO NOT USE A BLADE IN
THIS CONDITION !
FIGURE 4.1A
2.Replace the blade if it is badly chipped, bent, noticeably out of balance or has cracks or notch in either tip. See Figure 4.1 & 4.1A. Replace with new blade.
WARNING
Never use a cutting blade that shows signs of excessive wear or damage. Refer to Section on MOWER BLADE REPAIR/REPLACEMENT for proper blade inspection and service procedures.
4.1.2. BLADE SHARPENING
1.Disconnect spark plug wire and secure end away from plug.
2.Tilt mower up on its rear wheels. Do not tilt mower with spark plug or carburetor down.
3.Remove blade. See Figure 4.2.
MAKE SURE THAT
BLADE HUB IS
SEATED
BLADE BETWEEN
HUBFLANGES
FLANGE
BLADE
CONE WASHER (Concave Side Up)
CAPSCREW
FIGURE 4.2
4.Sharpen blade on a grinding wheel at an angle of
22to 28 degrees. DO NOT sharpen blade beyond original cutting edge. See Figure 4.3.
DO NOT SHARPEN BEYOND
ORIGINAL
CUTTING EDGE
BLADE TIP
END VIEW OF
BLADE ASSEMBLY
ORIGINAL CUTTING EDGE
FIGURE 4.3
5.Check blade for balance. If necessary, correct balance by grinding heavy end of blade.
6.Reinstall blade. Refer to Figure 4.1. Check torque of blade retaining cap screw. Recommended torque should be 30 to 40 ft. lbs.
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