Scag Genuine 21-inch Cutter Blade (Part S482879) Instruction Manual

1. Product Overview

This manual provides essential information for the safe handling, installation, and maintenance of the Scag Genuine 21-inch Cutter Blade, part number S482879. This blade is designed for specific Scag lawn mower models to ensure optimal cutting performance and safety.

Figure 1: Scag Genuine 21-inch Cutter Blade (Part S482879). This image displays the black metal blade with a central mounting hole and two notched ends, characteristic of a standard lawn mower cutter blade.

Part Number: S482879 (Replaces 482879)

Package Quantity: 1 Cutter Blade

Compatible Models (Partial List):

• SFZ48-19KA, SFZ48-20FS, SFZ48-26BS
• SFZ52-19KA, SFZ52-20FS, SFZ52-26BS
• SFZ61-24FS, SFZ61-730FS
• SFZP52-23FS, SFZP52-25BS
• SFZP61-24FS, SFZP61-27BS
• SM-61A, SM-61V, SMFZ-48, SMFZ-52, SMFZ-61
• SMT-52A, SMT-61A, SMT-61V, SMT-72V, SMT-72VS
• SMTC-48V, SMWC-52V, SMWC-61A, SMWC-61V
• SPZ61-23FX
• STC48V-26BS, STC52V-25CV, STC52V-27CV-SS, STC61V-730FX, STCII-61V-29CV-EFI
• STHM-23CV
• STT-28CAT-SS, STT-29CH-EFI, STT-31EFI-SS, STT-35BVAC, STT-35BVAC-SS
• STT52V-27CH, STT52V-29CH-EFI
• STT61A-27CH, STT61A-27KA, STT61A-29KA-DFI
• STT61V-791DFI
• STT72V-25KBD, STT72V-35BVAC, STT-791DFI
• STTII-52V-26CH-EFI, STTII-61V-25KA, STTII-72V-31DFI
• STWC61A-27CV
• SWZT61-22FSE

Always verify the original part number in your mower's owner's manual or on the appropriate parts diagram for correct location and fitment.

2. Safety Information

WARNING: Lawn mower blades are sharp and can cause severe injury. Always exercise extreme caution when handling, installing, or removing blades.

• Always wear heavy-duty gloves and eye protection when handling blades.
• Ensure the lawn mower engine is turned off, the spark plug wire is disconnected, and the machine is cool before performing any maintenance or blade replacement.
• Block the mower deck to prevent accidental movement if lifting the mower.
• Never attempt to sharpen or modify a damaged blade. Replace it with a new, genuine Scag blade.
• Keep hands and feet clear of the blade area at all times.

3. Setup and Installation

Replacing a lawn mower blade requires careful attention to detail. Refer to your specific Scag lawn mower's owner's manual for detailed instructions and torque specifications.

1. Prepare the Mower: Park the mower on a flat, level surface. Turn off the engine, remove the ignition key, and disconnect the spark plug wire to prevent accidental starting. Allow the engine and blade to cool.
2. Access the Blade: Depending on your mower model, you may need to lift the front of the mower or remove the mower deck. Secure the mower in a stable position using jack stands or blocks.
3. Remove Old Blade: Use a blade removal tool or a block of wood to prevent the blade from turning. Using an appropriately sized wrench, loosen and remove the blade bolt(s) and any washers. Note the orientation of the blade and washers for correct reinstallation.
4. Inspect Components: Inspect the blade spindle, washers, and bolt for wear or damage. Replace any worn or damaged parts. Clean any grass clippings or debris from the blade mounting area.
5. Install New Blade: Position the new Scag Genuine 21-inch Cutter Blade (Part S482879) with the cutting edge facing the correct direction (typically towards the direction of rotation, often indicated by an arrow on the blade or deck). Ensure the blade is centered on the spindle.
6. Secure Blade: Reinstall any washers and the blade bolt(s). Tighten the blade bolt(s) to the torque specifications provided in your mower's owner's manual. Overtightening or undertightening can lead to damage or unsafe operation.
7. Final Checks: Reconnect the spark plug wire and remove any blocks or stands. Ensure the blade spins freely without obstruction.

4. Operating Considerations

After installing the new blade, ensure all safety guards are in place and properly secured before operating the lawn mower. Always operate the mower according to the instructions in your mower's owner's manual. A properly installed and balanced blade contributes to a clean cut and reduces mower vibration.

5. Maintenance

Regular inspection and maintenance of your mower blade are crucial for performance and safety.

• Inspection: Before each use, inspect the blade for excessive wear, bends, cracks, or nicks. A damaged blade can cause vibration, poor cutting, and potential hazards.
• Sharpening: While this blade can be sharpened, it is recommended to have it professionally sharpened to maintain proper balance and cutting angle. An unbalanced blade can cause severe vibration and damage to the mower.
• Replacement: Replace the blade if it is severely bent, cracked, or worn down. It is generally recommended to replace blades annually or more frequently depending on usage and terrain. Always replace with genuine Scag parts to ensure compatibility and performance.

6. Troubleshooting

If you experience issues after blade replacement, consider the following:

• Excessive Vibration: This is often caused by an unbalanced blade or improper installation. Recheck blade installation, ensuring it is centered and tightened to specifications. If vibration persists, the blade may be bent or improperly sharpened and should be replaced or professionally balanced.
• Poor Cut Quality: Ensure the blade is installed with the cutting edge facing the correct direction. A dull or damaged blade will also result in poor cut quality.
• Blade Not Spinning: Verify that the blade bolt is not overtightened to the point of binding, and that there are no obstructions in the blade path.

For persistent issues, consult your Scag lawn mower's owner's manual or contact an authorized Scag service center.

7. Specifications

8. Warranty and Support

This is a genuine Scag replacement part. For information regarding warranty coverage, please refer to the original product warranty documentation provided with your Scag lawn mower or contact an authorized Scag dealer. For technical support or specific inquiries about your mower model, please visit the official Scag website or contact their customer service.

Important: Use of non-genuine parts may void your mower's warranty and could compromise safety and performance.