MaxPower 331737B Mulching Blade User Manual
Model: 331737B | Brand: MaxPower
1. Product Overview
The MaxPower 331737B Mulching Blade is a high-quality replacement blade designed for various 21-inch cut lawn mowers, including models from Craftsman, Husqvarna, and Poulan. This blade is engineered to meet or exceed original equipment manufacturer (OEM) specifications, ensuring optimal performance and durability. It is specifically designed for mulching applications, finely cutting grass clippings and returning them to the lawn as natural fertilizer.
Figure 1.1: Front view of the MaxPower 331737B Mulching Blade. This image displays the blade's overall shape and the MaxPower branding label.
2. Specifications
The following table details the key specifications of the MaxPower 331737B Mulching Blade:
| Specification | Value |
|---|---|
| Model Number | 331737B |
| Blade Length | 21 inches |
| Blade Width | 2-1/4 inches |
| Center Hole Diameter | 5/8 inches |
| Item Weight | 2 pounds |
| Product Dimensions | 2 x 25 x 4 inches |
| Replaces OEM Numbers | 165833, 175064, 189028, 406712, 008020, 159267, 175052, 176135, 406706, 406712X431, 531300765, 532 15 92-67, 532 17 50-52, 532159267, 532165833, 532175064, 532176135, 532189028, 532406712, 539111878, PP23020 |
| Compatible Mowers | Many 21-inch cut Craftsman, Husqvarna, Poulan mowers, including Craftsman CMXGZAM100129 |
Figure 2.1: Graphic illustrating the key dimensions of the MaxPower 331737B Mulching Blade, including length, width, and center hole diameter.
Figure 2.2: Graphic showing the round center hole design of the MaxPower 331737B Mulching Blade, crucial for proper fitment.
3. Installation Instructions
Proper installation of the mulching blade is critical for safety and optimal performance. Always follow these steps carefully.
3.1 Safety Precautions
- Disconnect Spark Plug: Before performing any maintenance or installation, always disconnect the spark plug wire from the spark plug to prevent accidental engine starting.
- Wear Protective Gear: Wear heavy-duty gloves and eye protection to prevent injuries from sharp edges or debris.
- Stabilize Mower: Tilt the mower onto its side with the carburetor and air filter facing upwards to prevent fuel or oil leaks. Ensure the mower is stable and cannot tip over.
- Allow Engine to Cool: Ensure the engine and muffler are cool to the touch before beginning work.
3.2 Removing the Old Blade
- Locate the blade retaining bolt(s) in the center of the blade.
- Use a block of wood or a specialized blade removal tool to brace the blade against the mower deck, preventing it from turning while you loosen the bolt.
- Using a wrench or socket, turn the blade bolt counter-clockwise to loosen and remove it. Note that some mowers may have left-hand threads, requiring clockwise rotation to loosen.
- Carefully remove the old blade and any washers or spacers. Note their orientation for reinstallation.
3.3 Installing the New Blade
- Inspect the blade mounting area on the mower shaft for any debris or damage. Clean as necessary.
- Position the new MaxPower 331737B mulching blade onto the mower shaft. Ensure the cutting edges (the angled side of the blade) are pointing upwards towards the mower deck. The curved "wings" of the blade should also point upwards.
- Align the center hole and any alignment pins on the blade with the corresponding features on the mower shaft.
- Reinstall any washers or spacers in their original orientation.
- Insert the blade retaining bolt and tighten it clockwise (or counter-clockwise for left-hand threads) using a wrench. Use the block of wood or blade tool to brace the blade.
- Tighten the bolt securely to the manufacturer's recommended torque specifications, if available. Over-tightening or under-tightening can cause issues.
- Reconnect the spark plug wire before attempting to start the mower.
Figure 3.1: Illustration demonstrating the correct orientation for blade installation, with the cutting teeth pointing upwards towards the mower deck.
Figure 3.2: Information explaining what an OEM number is and its importance for selecting the correct replacement blade. Verifying the OEM number ensures proper fit and function.
4. Operation
Once the MaxPower 331737B mulching blade is correctly installed, operate your lawn mower according to its manufacturer's instructions. This mulching blade is designed to provide a fine cut and efficiently recirculate grass clippings. For best mulching results:
- Mow when grass is dry.
- Avoid cutting more than one-third of the grass blade length at a time.
- Maintain a consistent mowing speed.
- Ensure the blade is sharp for optimal cutting and mulching performance.
5. Maintenance
Regular maintenance of your mulching blade will extend its lifespan and ensure consistent cutting performance.
5.1 Blade Sharpening
Over time, the blade's cutting edges will become dull. A dull blade tears grass, leading to an unhealthy lawn and increased strain on the mower engine. Sharpen the blade regularly using a file or a grinding wheel. Maintain the original cutting angle. Ensure the blade remains balanced after sharpening to prevent excessive vibration.
5.2 Cleaning and Inspection
After each use, especially when mulching, grass clippings can accumulate on the underside of the mower deck and on the blade. Disconnect the spark plug wire and clean off any buildup. Inspect the blade for any signs of damage, such as bends, cracks, or excessive wear. A damaged blade should be replaced immediately.
5.3 Storage
When storing the mower for extended periods, ensure the blade is clean and dry to prevent rust. Consider applying a light coat of oil to the blade for added protection.
6. Troubleshooting
This section addresses common issues related to mulching blade performance.
| Problem | Possible Cause | Solution |
|---|---|---|
| Poor Cut Quality / Uneven Cut | Dull blade; Blade installed upside down; Bent blade; Excessive grass height or wet grass. | Sharpen or replace blade; Reinstall blade with cutting edge pointing up; Replace blade; Mow dry grass, cut less at a time. |
| Excessive Mower Vibration | Unbalanced blade (due to sharpening or damage); Bent crankshaft. | Balance or replace blade; Consult a qualified service technician for crankshaft issues. |
| Blade Not Mulching Effectively | Dull blade; Mowing too fast; Grass too tall or wet; Incorrect blade type for mulching. | Sharpen blade; Reduce mowing speed; Mow dry grass, cut less at a time; Ensure you are using a mulching-specific blade. |
7. Warranty and Support
MaxPower blades are proudly manufactured in the USA to meet or exceed OEM specifications. While specific warranty details are not provided in this manual, MaxPower stands behind the quality of its products.
For any questions regarding product performance, compatibility, or to report a defect, please contact MaxPower customer support. When contacting support, please have your product model number (331737B) and any relevant purchase information available.
You can find more information and contact details on the official MaxPower website or through your product retailer.
