1. Introduction
This manual provides essential information for the safe and efficient operation, maintenance, and troubleshooting of your PowerSmart 21-inch 140cc B&S Self-Propelled Lawn Mower. Please read this manual thoroughly before operating the mower and keep it for future reference.
Image 1.1: PowerSmart 21-inch Self-Propelled Lawn Mower. This image shows the mower's overall design, including the engine, handle, and grass collection bag.
2. Safety Information
Always follow basic safety precautions to reduce the risk of fire, electric shock, and personal injury. This section outlines critical safety guidelines.
General Safety Rules
- Read and understand all instructions before operating the machine.
- Keep children and pets away from the mowing area.
- Wear appropriate personal protective equipment (PPE), including eye protection, hearing protection, and sturdy footwear.
- Never operate the mower when barefoot or wearing open sandals.
- Inspect the area where the mower is to be used and remove all objects that can be thrown by the blade.
- Do not operate the mower in wet grass or rain.
- Always turn off the engine and disconnect the spark plug wire before cleaning, repairing, or inspecting the mower.
3. Setup and Assembly
3.1 Unpacking and Handle Assembly
Carefully remove the mower from its packaging. The handle typically comes folded for shipping. Unfold the handle and secure it using the provided knobs or levers. Ensure all cables are properly routed and not pinched.
3.2 Adding Engine Oil and Fuel
Before first use, add the recommended engine oil and fresh gasoline. Refer to the engine manual for specific oil type and capacity. Do not overfill.
- Locate the oil fill cap/dipstick and add the correct amount of 10W-30 engine oil.
- Fill the fuel tank with fresh, unleaded gasoline.
Image 3.1: Engine Detail. This image highlights the Briggs & Stratton 140cc engine, showing where to add oil and fuel.
3.3 Adjusting Cutting Height
This mower features 6 height settings to customize your cut. Adjust the cutting height by moving the lever on each wheel assembly to the desired position. Ensure all wheels are set to the same height.
Image 3.2: Height Adjustment. This image illustrates the lever used to adjust the cutting height, with indicators for different settings.
4. Operating Instructions
4.1 Starting the Engine
The PowerSmart mower is equipped with an easy-pull recoil and auto choke system for convenient instant starting. No priming is required.
- Ensure the fuel tank is filled and the oil level is correct.
- Stand behind the mower and firmly grasp the handle.
- Pull the starter cord with a quick, continuous motion until the engine starts.
4.2 Using the Self-Propel Feature
The self-propel function assists in moving the mower forward, reducing operator effort. Engage the self-propel lever on the handle to activate the drive system. Release the lever to disengage.
4.3 3-in-1 Versatility: Mulching, Bagging, and Rear Discharge
Your mower offers three cutting options:
- Bagging: Attach the grass collection bag to collect clippings for a clean lawn.
- Mulching: Remove the grass bag and ensure the mulching plug is in place (if applicable) to finely shred clippings and return them to the lawn as fertilizer.
- Rear Discharge: Remove the grass bag and mulching plug (if applicable) to allow clippings to be discharged from the rear of the mower.
Image 4.1: 3-in-1 Functionality. This image visually explains the mulching, rear discharge, and rear bagging options.
4.4 Stopping the Engine
Release the engine control bar on the handle to stop the engine. The blade will stop rotating within a few seconds.
5. Maintenance
Regular maintenance ensures optimal performance and extends the life of your lawn mower. Always disconnect the spark plug wire before performing any maintenance.
5.1 General Cleaning
After each use, clean grass clippings and debris from the mower deck, wheels, and engine cooling fins. Use a brush or cloth. Avoid using high-pressure water directly on the engine.
5.2 Engine Maintenance
- Oil Change: Change engine oil after the first 5 hours of operation, then every 25 hours or annually.
- Air Filter: Inspect and clean the air filter regularly. Replace if damaged or excessively dirty.
- Spark Plug: Inspect the spark plug annually. Clean or replace as needed.
5.3 Blade Care
Regularly inspect the cutting blade for sharpness and damage. A dull blade tears grass, leading to an unhealthy lawn. Sharpen or replace the blade as necessary. Always wear heavy gloves when handling the blade.
Image 5.1: Cutting Blade. This image provides a view of the mower's underside, highlighting the cutting blade and the robust steel deck construction.
5.4 Storage
For long-term storage, especially over winter, prepare the mower as follows:
- Drain the fuel tank or add a fuel stabilizer.
- Change the engine oil.
- Clean the mower thoroughly.
- Store in a dry, well-ventilated area. The handle can be folded for compact storage.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Engine does not start | No fuel, old fuel, spark plug disconnected, low oil. | Add fresh fuel, check spark plug connection, ensure adequate oil level. |
| Mower cuts unevenly | Dull blade, incorrect cutting height setting, uneven terrain. | Sharpen or replace blade, adjust cutting height evenly, mow on level ground. |
| Excessive vibration | Bent or unbalanced blade, loose engine bolts. | Inspect and replace blade if bent, tighten engine bolts. |
7. Specifications
| Feature | Detail |
|---|---|
| Brand | PowerSmart |
| Model Number | B8721S2 |
| Engine | 140cc B&S EX550 |
| Cutting Deck Width | 21 inches |
| Cutting Height Positions | 6 |
| Operation Modes | 3-in-1 (Bagging, Mulching, Rear Discharge) |
| Drive Type | Self-Propelled |
| Material | Alloy Steel Deck |
| Item Weight | 33.11 Kilograms |
| UPC | 840432709146 |
8. Warranty and Support
PowerSmart products are designed for durability and performance. For warranty information, please refer to the separate warranty card included with your purchase or visit the official PowerSmart website. For technical assistance or parts, contact PowerSmart customer service.
Customer Service Email: support2@powersmartusa.com
PowerSmart has over 500 certified repair centers in the U.S. and provides full replacement parts through its IL headquarters.
Image 8.1: PowerSmart Customer Support. This image shows the PowerSmart support team and contact information.