PowerSmart 21" 3-in-1 Gas Push Lawn Mower with 140cc 4-Stroke Engine - Wide Cutting Deck, 6 Height Adjustments, Mulching Capability

Why I Chose This Mower

I wanted a straightforward, gas-powered push mower that didn’t require babying or complicated maintenance. The PowerSmart 21-inch mower ticked the right boxes on paper: a 140cc 4-stroke engine (no mixing oil and gas), a 21-inch steel deck, and true 3‑in‑1 capability for side discharge, rear bagging, and mulching. After a season of use on a suburban lot with mixed turf and a couple of gradual slopes, I’ve got a solid sense of where it shines—and where it asks for a little patience.

Setup and First Impressions

Out of the box, setup was minimal: add oil, fuel, attach the bag if you plan to bag, and go. The deck is steel and feels sturdier than the price category usually affords. The finish resisted scuffs from errant sticks and edging stones better than I expected. The controls are as simple as they come, with a no-nonsense pull cord and a standard bail bar. Nothing fancy, and that’s part of its appeal.

The 21-inch deck is a practical sweet spot for small to medium yards. It saves a few passes versus 18–20-inch mowers without feeling awkward around tight landscaping. Clearance under the deck is generous enough that clumping was only an issue when I tried to mow wet grass—no surprise there.

Engine and Starting

The 140cc 4-stroke engine is the right size for a push mower in this class. It started reliably for me—usually on the first or second pull—even after sitting for a couple of weeks. Because it’s a 4-stroke, there’s no oil/gas mixing; just keep the oil topped off and clean. It’s not a high-revving, brute-force mill, but it’s well-matched for weekly cuts and average turf density. If your lawn tends to get overgrown or you like to cut very low, it’s capable, but you may need to plan your passes.

Noise is typical for a gas mower. I wore hearing protection for longer sessions and would recommend the same.

Cut Quality and Height Adjustments

Cut quality is consistent when you stay within the one-third rule—removing no more than one-third of the grass blade at a time. The mower offers six cutting heights between 1.5 and 3.9 inches, which covers most cool- and warm-season grass recommendations. I tended to mow at 2.75–3.25 inches for my mix of Kentucky bluegrass and perennial rye, and the result was an even, healthy-looking finish.

Switching height is straightforward, and the steps are clearly defined. If you’re dealing with a lawn that occasionally gets away from you, the upper end of the range (around 3.5–3.9 inches) is actually important—start high for the first pass to reduce load and improve airflow under the deck, then step down if you want a crisper final cut.

3‑in‑1 Versatility in Practice

• Side discharge: This is the mode I used for quick weekly cuts. It moves through average growth efficiently and keeps the deck clear in damp conditions. If you edge after mowing, you’ll want to direct the chute away from beds and sidewalks.
• Rear bagging: The bag fits cleanly, captures clippings effectively, and is easy to detach and empty. Like most 21-inch bags, capacity isn’t huge; expect more frequent emptying if you’re cutting taller grass.
• Mulching: With the plug in, mulching performance was solid on dry, moderately tall grass. The deck produces adequate lift and recirculation to reduce clippings to fine pieces. In dense or wet conditions, I noticed more resistance and occasional clumping; a two-pass strategy (higher first, then normal height) helped. Keeping the blade sharp makes a noticeable difference here.

Maneuverability and Effort

This is a push mower, not self-propelled, so your experience will vary with terrain and turf density. On flat sections and weekly growth, it felt reasonably light for a steel-deck gasser and moved without drama. Around beds and trees, the 21-inch deck remained manageable.

Where I had to work harder was in thick, lush sections—especially when I tried to cut low. The mower’s airflow and suction, which help stand up blades for a clean cut, also increase rolling resistance in dense grass. On my gentle slope, I needed to slow my pace and raise the deck a notch to keep things smooth. If your yard is hilly or you prefer lower cuts in heavy turf, be prepared for more push effort. Technique helps:
- Raise the cutting height for an initial pass, then step down.
- Take narrower swaths in the toughest areas.
- Keep the blade sharp to reduce drag and load on the engine.

Build Quality and Durability

The steel deck and frame feel tough, with no rattles beyond the usual engine vibration. The handle has minimal flex under normal use and locks down securely. After a season, I didn’t notice any premature wear on the deck or the common pinch points at the handle pivots. As with any steel deck, rinsing off dry clippings and occasionally inspecting for nicks in the paint will help stave off corrosion. The red finish cleans up well.

Maintenance Notes

Basic 4-stroke mower care applies:
- Check oil before each mow the first few outings, then regularly thereafter.
- Replace or clean the air filter as needed (more often if you mulch dusty areas).
- Sharpen the blade at least once per season, more often if you hit debris.
- Run fresh, ethanol-treated fuel; avoid letting fuel sit in the tank for months.

Access to the spark plug and blade is straightforward, and nothing about routine maintenance felt fussy. I appreciate that this platform doesn’t depend on proprietary gimmicks to keep running.

What Could Be Better

• Push effort in heavy turf: Without self-propulsion, the mower can feel heavy in thick or overgrown grass, especially at low height settings. The engine has enough power for the cut, but airflow and suction increase resistance. Technique mitigates it, but users with hills or very dense lawns might find it tiring.
• Bag capacity is typical, not generous: That’s par for the class, but if you bag regularly on a larger lot, plan on more trips to the compost bin.
• Documentation and parts ecosystem: The included manual covers the basics, but I would like clearer guidance on blade specifications and a readily visible parts list. If you’re the type who keeps a mower for many seasons, easy access to consumables (belts aren’t applicable here, but blades, filters, and cables) matters.

Who It’s For

• Small to medium lawns where a 21-inch deck strikes the right balance of speed and maneuverability.
• Owners who mow weekly or close to it and want predictable, low-fuss operation.
• Users who value 3‑in‑1 flexibility and primarily cut on flat to gently sloped terrain.
• DIYers comfortable with basic maintenance and blade sharpening.

If you have steep slopes, routinely mow tall, thick grass, or prefer very low cuts, consider whether a self-propelled model would better fit your needs.

The Bottom Line

The PowerSmart 21-inch mower is a practical, no-frills gas push mower that gets the fundamentals right: dependable starting, a strong enough 140cc engine for weekly cuts, a durable steel deck, and credible performance across side discharge, bagging, and mulching. It rewards good mowing habits—sharp blade, appropriate height, reasonable pace—with a clean, even finish.

It’s not without trade-offs. In dense turf or on slopes, expect more push effort than lighter or self-propelled alternatives. And while the 3‑in‑1 setup covers all common scenarios, bag capacity and wet-grass mulching are limited by physics and class, not by glaring design flaws.

Recommendation: I recommend this mower for homeowners with small to medium, mostly flat lawns who want a straightforward, budget-friendly gas push mower that’s easy to start and maintain. If your yard is hilly or your grass frequently gets overgrown, a self-propelled model or a higher-torque setup may suit you better. For the right yard, though, this PowerSmart delivers reliable, uncomplicated mowing at a sensible size and feature set.