Briggs & Stratton NSPVH21675 Lawn Mower User Manual


 
Mower Blade Replacement
Standard Blade Wear Limit
1. Inspect the blade (Figure 15) 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.
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.
Important: 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 16).
4. Sharpen the blade on a grinding wheel at an angle of 22
to 28 degrees (B, Figure 17). 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 16). 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 should be 40 ft. lbs.
WARNING
DO NOT attempt any maintenance, adjustments or service
with engine and blade running. STOP engine and blade.
Disconnect spark plug wire and secure away from spark
plug. Engine and components are HOT. Avoid serious
burns, allow sufficient time for all components to cool.
Wear heavy leather gloves when handling or working
around cutting blades. Blades are extremely sharp and can
cause severe injury.
!
!
Figure 15: Mower blade wear limits
A
B
C
WARNING
DO NOT use a cutting blade that shows signs of excessive
wear or damage. Refer to the Section entitled “MOWER
BLADE REPLACEMENT” for proper blade inspection and
service procedures.
!
!
Make sure that
blade hub is seated
between flanges
Figure 16: Removing the mower blade
Do not sharpen
beyond original
cutting edge
End view of
blade assembly
22-28
0
Figure 17: Sharpening the mower blade
A
B
C
A
B
D
E
Maintenance
11