Introduction
This manual provides essential information for the safe and effective installation, operation, and maintenance of your Arnold 42-inch Mulching Blade Set. Please read these instructions thoroughly before attempting any installation or maintenance procedures. Proper use and care will ensure optimal performance and longevity of your blades.
Safety Information
Always prioritize safety when working with lawn mower blades. Failure to follow these safety guidelines can result in serious injury.
- Disconnect Spark Plug: Before performing any work on the mower deck or blades, always disconnect the spark plug wire to prevent accidental engine starting.
- Wear Protective Gear: Always wear heavy-duty gloves and eye protection when handling blades. Blades are sharp and can cause cuts.
- Secure the Mower: Ensure the lawn mower is on a flat, stable surface and cannot roll or tip over during blade replacement. Use jack stands if lifting the mower.
- Engine Cool Down: Allow the engine and muffler to cool completely before working on the mower to avoid burns.
- Proper Torque: Ensure all fasteners are tightened to the manufacturer's specified torque to prevent blades from loosening during operation.
Compatibility
This Arnold 42-inch Mulching Blade Set (Model 490-110-M115) is designed for use with 42-inch lawn and garden tractors manufactured in 1997 and after. It is compatible with various brands, including:
- MTD
- Troy-Bilt
- Yard-Man
- Huskee
- Yard Machines
- Bolens
These blades feature a star center hole design. They replace Original Equipment (O.E.) part numbers 942-0616, 942-0616A, 742-0616, and 742-0616A.
Package Contents
Your Arnold 42-inch Mulching Blade Set package includes:
- Two (2) 42-inch Mulching Blades
Image: The Arnold 42-inch Mulching Blade Set, showing two black blades with star-shaped center holes, standing vertically.
Installation
Tools Required
- Heavy-duty work gloves
- Safety glasses
- Wrench or socket set (appropriate size for blade bolts)
- Torque wrench
- Wood block or blade removal tool
Step-by-Step Blade Replacement
- Prepare the Mower: Park the lawn mower on a flat, level surface. Turn off the engine, engage the parking brake, and remove the ignition key. Disconnect the spark plug wire to prevent accidental starting.
- Access the Blades: Depending on your mower model, you may need to raise the front of the mower or remove the mower deck. Refer to your mower's owner's manual for specific instructions on accessing the blades.
- Secure the Blade: Place a wood block between the blade and the mower deck to prevent the blade from turning while you loosen the bolt.
- Remove Old Blades: Using a wrench or socket, loosen and remove the blade bolt. Note the orientation of the old blade before removal. Blades typically have a cutting edge that faces towards the ground.
- Inspect Components: Examine the blade spindle and mounting hardware for any damage or wear. Replace any worn components as necessary.
- Install New Blades: Position the new Arnold mulching blade onto the spindle, ensuring the cutting edge faces the ground. The star-shaped center hole should align perfectly with the spindle.
Image: A pair of Arnold 42-inch mulching blades laid flat, highlighting the star-shaped center hole for proper spindle alignment.
- Tighten Blade Bolts: Reinstall the blade bolt and washer. Use a torque wrench to tighten the bolt to the torque specification provided in your mower's owner's manual. Typically, this is between 70-90 ft-lbs (95-122 Nm). Overtightening or undertightening can be dangerous.
- Reassemble Mower: Reattach the mower deck (if removed) and lower the mower. Reconnect the spark plug wire.
- Test Operation: Before mowing, start the engine and listen for any unusual noises or vibrations. If any issues are detected, immediately shut off the engine and re-inspect the blade installation.
Operating Instructions
These 3-in-1 blades are designed for mulching, bagging, and side discharge operations. The specific method of operation depends on your mower's configuration and accessories.
- Mulching: When mulching, the blades are designed to cut grass into fine clippings that are then recirculated back into the lawn as natural fertilizer. Ensure your mower's mulching plug or baffle is correctly installed.
- Bagging: For bagging operations, attach the grass collection bag to your mower. The blades will create airflow to direct clippings into the bag.
- Side Discharge: If your mower is set up for side discharge, the blades will propel clippings out of the side chute.
Always operate your mower according to its owner's manual. Avoid mowing wet grass, as it can clog the deck and reduce cutting performance.
Maintenance
Regular maintenance of your blades ensures optimal cutting performance and safety.
- Clean Blades: After each use, clean grass clippings and debris from the blades and underside of the mower deck. This prevents rust and maintains balance.
- Inspect for Damage: Regularly inspect blades for bends, cracks, or excessive wear. Damaged blades should be replaced immediately.
- Sharpening: Blades should be sharpened periodically to maintain a clean cut. If sharpening, ensure the blade remains balanced. An unbalanced blade can cause excessive vibration and damage to the mower. If you are unsure how to sharpen blades correctly, consult a professional.
- Storage: When storing the mower for extended periods, ensure blades are clean, dry, and lightly oiled to prevent rust.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Uneven cut | Dull or bent blades; uneven tire pressure; mower deck not level. | Sharpen or replace blades; check and adjust tire pressure; level mower deck. |
| Excessive vibration | Unbalanced or bent blades; loose blade bolts; debris on blades/spindle. | Inspect and balance/replace blades; tighten blade bolts to specification; clean blades and spindle. |
| Poor mulching/bagging | Dull blades; mowing wet or excessively tall grass; clogged deck. | Sharpen blades; mow dry grass at appropriate height; clean mower deck. |
Specifications
- Product Dimensions: 23 x 5 x 5 inches
- Item Weight: 4 pounds
- Model Number: 490-110-M115
- Blade Type: 3-in-1 Mulching Blade
- Center Hole: Star-shaped
- Quantity: 2 blades per set
Warranty and Support
For specific warranty information or technical support regarding your Arnold Mulching Blade Set, please refer to the Arnold Corporation's official website or contact their customer service. Keep your purchase receipt for warranty claims.
Proposition 65 Warning
WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
