AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower, 144cc vs RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah
Updated July 2026 — AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower, 144cc wins on engine size and weight, RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah wins on storage space and battery.
The AMERISUN offers more power and versatility, while the RB is a lightweight, budget-friendly option for small spaces.
Why AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower, 144cc is better
Power
144cc engine vs 40V battery
Cutting Width
21 inches vs 9 inches
Versatility
3-in-1 functionality vs limited features
Why RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah is better
Weight
11.5 lbs vs 68 lbs
Price
$169.99 vs $238.49
Storage
Upright storage vs foldable handle
Overall score
Specifications
| Spec | AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower, 144cc | RB 9" Small Lawn Mower for Small Spaces, 40V 2Ah |
|---|---|---|
| Engine Type | 4-Cycle OHV | Brushless Motor |
| Power Source | Gas | Battery |
| Cutting Heights | 6 | 3 |
| Safety Features | Standard | Advanced |
| Mowing Area | Medium | Small |
Dimension comparison
Overview of the AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower
The AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower is designed for small to medium-sized lawns, featuring a powerful 144cc 4-cycle OHV engine. Priced at $238.49, it ranks 8,653 in sales, indicating a solid presence in the market. The mower emphasizes versatile functionality with mulching, bagging, and side discharge options, making it a great choice for homeowners looking for a reliable gas-powered solution.
The mower's 21-inch cutting deck is made of durable steel, ensuring longevity and effective performance in various grass conditions. With six height adjustments ranging from 1.5" to 3.9", it accommodates different lawn care needs, presenting a well-rounded option for those with a bit more yard to maintain.
Overview of the RB 9" Small Lawn Mower for Small Spaces
The RB 9" Small Lawn Mower is an ultra-light, cordless option ideal for tiny yards, priced at $169.99. It ranks 20,912 in sales, catering specifically to those with limited lawn space. This mower features a 40V 2Ah battery and a high-speed brushless motor, delivering efficient cutting power for lawns up to 540 square feet.
With a compact design and weight of only 11.5 lbs (without battery), it is easy to maneuver through tight corners. The adjustable cutting height offers three settings from 1.2" to 2", allowing for tailored grass maintenance. This makes it an attractive option for small property owners seeking a low-maintenance lawn care solution.
Price Comparison
When comparing prices, the AMERISUN is priced at $238.49, while the RB is about $69 cheaper at $169.99. This makes the RB approximately 29% less expensive than the AMERISUN, which could be a significant factor for budget-conscious consumers. However, the extra cost of the AMERISUN can be justified by its larger cutting width and more powerful engine, which may be necessary for those with more extensive lawn care needs.
For those who prioritize initial investment over long-term functionality, the RB presents a compelling, cost-effective alternative without sacrificing too much in performance for small spaces.
Engine and Power
The AMERISUN features a robust 144cc 4-cycle OHV engine, which is particularly beneficial for those needing consistent power and performance across small to medium lawns. This engine type ensures effective cutting and mulching, making it suitable for various grass types and challenging lawn conditions.
In contrast, the RB utilizes a 40V 2Ah battery and a brushless motor that operates at 6000 RPM. This setup is designed for efficiency in small yards, requiring no maintenance and providing adequate power for lawns up to 540 square feet. While the RB's motor is efficient for small areas, it may lack the cutting power needed for larger or denser grass conditions that the AMERISUN can handle.
Cutting Width and Versatility
The AMERISUN boasts a cutting width of 21 inches, providing a broader mowing path that can significantly reduce mowing time, especially for those with larger areas. This versatility is further enhanced by its 3-in-1 capability—mulching, bagging, and side discharge—making it adaptable for various lawn care preferences.
On the other hand, the RB is more limited with a 9-inch cutting width, which makes it specifically suited for small spaces and light tasks. Its design supports three cutting heights, but the smaller width means more passes are required to cover the same area compared to the AMERISUN. Thus, while the RB is excellent for tight spots, it may not be the best choice for those wanting a quicker mowing experience.
Maneuverability and Design
Weighing in at 68 lbs, the AMERISUN is designed for stability and control, featuring 7-inch front and 10-inch rear wheels that assist in maneuvering around obstacles in the yard. Its foldable handle makes it easier to store, appealing to users with limited storage space.
Conversely, the RB is incredibly lightweight at just 11.5 lbs without the battery, making it highly maneuverable. Its pivoting front wheels and one-hand steering design cater to those navigating tight corners and small areas, which is a significant advantage for homeowners with compact lawns. Additionally, its upright storage capability saves space, making it a practical choice for those with minimal storage options.
Safety Features
The AMERISUN does not specifically highlight safety features in its description, which might be a consideration for safety-conscious consumers. However, it’s built with a reliable engine and standard safety protocols typical of gas-powered mowers.
In contrast, the RB includes advanced safety features, automatically stopping if tilted beyond certain angles, which aligns with US safety standards. This makes it a reliable option for beginners or those unfamiliar with operating lawn mowers, providing peace of mind for users concerned about safety during operation.
Which should you buy?
Choosing between the AMERISUN 21-Inch 3IN1 Gas Push Lawn Mower and the RB 9" Small Lawn Mower for Small Spaces largely depends on your specific lawn care needs. If you have a small to medium yard and require a powerful, versatile mower capable of handling various grass types, the AMERISUN is a strong contender despite being priced higher at $238.49.
Alternatively, if your main concern is a compact and lightweight solution for a small yard, the RB, priced at $169.99, is more budget-friendly and offers sufficient power for limited spaces. Ultimately, your decision should reflect the size of your yard, your budget, and your preferred mowing experience.

