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You need the best lawn mowers with 4-Stroke engines for reliable power and consistent performance. We compared 6 models using only their published specifications. Our top pick is the PowerSmart 21-Inch 170cc Self-Propelled Gas Mower, which leads due to its 170cc engine displacement and self-propelled drive for uneven terrain. These selections are based strictly on data like cutting width, engine stroke, and drive type. This guide helps you decide which machine fits your lawn size and terrain needs.
Match Drive Type to Your Lawn Slope
Choose self-propelled models for uneven terrain or slopes. The top pick features rear-wheel drive and a 170cc engine for reliable traction. Use push mowers for flat, small lawns to save weight. Check the drive type and engine displacement in the specs to ensure the machine matches your yard's specific conditions and your physical effort preferences.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | PowerSmart 21-Inch 170cc Self-Propelled Gas Mower Best overall | uneven terrain and slope mowing | |
| 2 | PowerSmart 21-Inch 140cc Gas Push Mower Best budget | small lawns needing mulching and bagging | |
| 3 | Sang Seiyoga 16-Inch Gas Scarifier Best premium | specialized lawn dethatching and scarifying tasks | |
| 4 | ALYIAMXL 16in Gas 2-in-1 Dethatcher Also great | seasonal lawn aeration and dethatching | |
| 5 | ZeHuoGe 16-Inch Gas Scarifier Also great | dethatching and scarifying compacted lawns | |
| 6 | PowerSmart 21-Inch 144cc Gas Push Mower Best 144cc | Flat lawns needing a wide 21-inch cut |
The best fit for you
- You need traction on uneven terrain – PowerSmart 21-Inch 170cc Self-Propelled Gas Mower – Its 170cc engine and rear-wheel drive provide stability on slopes.
- You want the most compact model – PowerSmart 21-Inch 144cc Gas Push Mower – It weighs only 44 pounds and measures 33 inches long.
- You need a high-capacity collection bag – Sang Seiyoga 16-Inch Gas Scarifier – The 13.2-gallon bag handles debris from dethatching tasks efficiently.
- You prefer a lightweight push mower – PowerSmart 21-Inch 140cc Gas Push Mower – This 140cc unit lacks self-propulsion, keeping weight manageable for small yards.
Is a 4-Stroke Engine Worth the Choice?
All 6 models in this list use 4-Stroke engines. This design separates oil from fuel, which simplifies maintenance since you do not need to mix oil into the gas tank. It also tends to produce fewer emissions and runs smoother than older 2-Stroke designs. Since every option here uses this technology, you do not need to compare stroke types. You simply choose based on cutting width, drive type, and engine displacement.
Worth it if
- You prefer simpler fuel maintenance without mixing oil
- You want consistent engine performance across all models
- You value lower emissions and smoother operation
Skip it if
- You are comparing 2-Stroke models for specific weight reasons
- You need a battery-powered electric mower instead
- You are looking for 2-Stroke specific vintage parts
PowerSmart 21-Inch 170cc Self-Propelled Gas Mower
Best for: uneven terrain and slope mowing
- Engine Stroke
- 4-Stroke
- Cutting Width
- 21 in
- Drive Type
- Self-propelled (rear-wheel drive)
- Mowing Functions
- 3-in-1 (mulch, side discharge, bag)
- Motor Type
- 4-stroke OHV, 170 cc
- Height Adjustments
- 6 positions (1.5" – 3.9")
This PowerSmart mower features a 170cc 4-stroke OHV engine and rear-wheel drive self-propulsion. The 21-inch steel deck offers 3-in-1 mulching, side discharge, or bagging options. You can adjust the cutting height across six positions from 1.5 to 3.9 inches. The foldable handle simplifies storage. It suits users needing reliable traction on uneven terrain without excessive effort.
- 170cc 4-stroke OHV engine for efficient cutting
- Rear-wheel drive self-propulsion for slope control
- 21-inch steel deck for durability
- 6-position height adjustment from 1.5 to 3.9 inches
- 59-pound weight may be heavy for some users
- 170cc engine displacement is lower than 212cc competitors
- You mow on slopes or uneven terrain
- You need rear-wheel drive for better traction
- You want a durable steel deck
- You prefer a lighter mower under 50 pounds
- You need more than 170cc engine power
- You require front-wheel drive
Verdict: PowerSmart 21" 170cc Self-Propelled Gas Mower fits homeowners who need reliable traction on uneven lawns. Its rear-wheel drive and steel deck provide stability and durability for consistent mowing results.
PowerSmart 21-Inch 140cc Gas Push Mower
Best for: small lawns needing mulching and bagging
- Engine Stroke
- 4-Stroke
- Cutting Width
- 21"
- Drive Type
- Push
- Mowing Functions
- 3-in-1 (discharge, bagging, mulching)
- Motor Type
- 140cc Briggs&Stratton 4-stroke
- Height Adjustments
- 6 adjustments (1.5 to 3.9 inches)
This PowerSmart push mower features a 140cc Briggs & Stratton 4-stroke engine and a 21-inch cutting deck. It offers three mowing functions: side discharge, rear bagging, and mulching. You get six height adjustments from 1.5 to 3.9 inches. The steel deck provides durability. This model suits smaller yards where you prefer manual pushing over self-propelled drive systems.
- 140cc Briggs & Stratton 4-stroke engine
- 21-inch wide cutting deck
- 3-in-1 mowing functions
- 6 height adjustments (1.5 to 3.9 inches)
- Steel deck construction
- Push drive requires manual effort
- 140cc engine displacement is smaller than competitors
- 6 height settings are fewer than many rivals
- You have a small lawn under 5,000 square feet
- You want mulching and bagging options
- You prefer a simpler push mower
- You need self-propelled drive for hills
- You want a larger 22-inch deck
- You prefer a more powerful 170cc engine
Verdict: PowerSmart 21" 140cc Gas Push Mower fits users with small, flat lawns who want versatile cutting options without the weight of a self-propelled unit.
Sang Seiyoga 16-Inch Gas Scarifier
Best for: specialized lawn dethatching and scarifying tasks
- Engine Stroke
- 4-Stroke
- Motor Type
- 4-stroke gasoline
- Height Adjustments
- 5-step, -0.6in to +0.6in
- Cutting Width
- 16-Inch
- Engine Displacement
- 212cc
- Mowing Functions
- 2-in-1
This Sang Seiyoga unit is a 2-in-1 dethatcher and scarifier with a 16-inch working width. It uses a 212cc 4-stroke gasoline engine rated at 7 HP. The machine includes a 13.2-gallon collection bag for debris. You can adjust the cutting depth using a central lever with five settings. The steel build weighs 85 pounds and measures 51 inches long.
- 212cc 4-stroke gasoline engine delivers 7 HP of power
- 13.2-gallon collection bag reduces the need for frequent emptying
- 5-step central height adjustment for precise depth control
- Interchangeable cassettes allow switching between scarifying and dethatching
- 16-inch working width is narrower than the 21-inch mowers on this list
- 85-pound weight makes it bulkier and heavier than standard push mowers
- 5 cutting height settings offer fewer options than typical 4-stroke mowers
- You need to remove moss and thatch from compacted soil
- You prefer a gas-powered tool with EPA certification
- You want to switch between scarifying and dethatching without tools
- You primarily want to cut grass rather than aerate soil
- You prefer a lighter machine for easy maneuverability
- You need a wider cutting deck for large lawns
Verdict: Sang Seiyoga 16-Inch Gas Scarifier suits homeowners who need specialized soil aeration and dethatching rather than standard mowing. It fits those willing to manage a heavier, narrower tool for healthier lawn maintenance.
ALYIAMXL 16in Gas 2-in-1 Dethatcher
Best for: seasonal lawn aeration and dethatching
- Engine Stroke
- 4-Stroke
- Motor Type
- 4-stroke gasoline
- Cutting Width
- 16-Inch
- Power Type
- Gas
- Engine Displacement
- 212cc
- Mowing Functions
- 2-in-1
The ALYIAMXL 16-Inch Gas Dethatcher uses a 212cc 4-stroke engine to power its 16-inch working path. It includes interchangeable cassettes for dethatching and aerating. A 13.2-gallon collection bag captures debris. Five depth settings adjust from -0.6 to +0.6 inches. This unit suits established residential lawns needing seasonal maintenance of thatch and moss.
- 212cc 4-stroke gas engine provides steady power
- 16-inch working width covers lawn areas efficiently
- 13.2-gallon collection bag reduces follow-up cleanup
- 5-position depth control adjusts from -0.6 to +0.6 inches
- 16-inch cutting width is narrower than the 21-inch options on this list
- 85-pound weight makes it bulkier and heavier than standard push mowers
- 13.2-gallon bag capacity is smaller than typical mower debris bags
- You need to remove thatch and moss from established lawns
- You want interchangeable cassettes for dethatching and aerating
- You prefer a 4-stroke gas engine for steady power
- You only want to mow grass without dethatching
- You prefer a lighter push mower for easy maneuvering
- You need a wider 21-inch cutting path for speed
Verdict: ALYIAMXL 16-Inch Gas Dethatcher fits homeowners maintaining established lawns who need specific aeration and scarifying tools rather than a standard mower.
ZeHuoGe 16-Inch Gas Scarifier
Best for: dethatching and scarifying compacted lawns
- Engine Stroke
- 4-Stroke
- Motor Type
- 4-stroke gasoline
- Height Adjustments
- 5-position, -0.6 in to +0.6 in
- Cutting Width
- 16-Inch
- Power Type
- Gas
- Engine Displacement
- 212cc
This ZeHuoGe 2-in-1 gas lawn scarifier and dethatcher features a 212cc 4-stroke engine producing 7 HP. It offers a 16-inch working width and includes a 13.2-gallon debris collection bag. The unit has a 5-position height adjustment and a steel frame. It suits users needing targeted thatch removal rather than general mowing.
- 212cc 4-stroke EPA-certified gasoline engine
- 16-inch working width for focused tasks
- 13.2-gallon debris collection bag
- 5-position central height adjustment lever
- Tool-free interchangeable cassettes
- 16-inch width is narrower than the 21-inch options on this list
- 85-pound weight makes it heavier to maneuver
- No mulching or bagging grass collection function
- You need to remove moss and thatch from compacted soil
- You want a dedicated 4-stroke gas tool for lawn aeration
- You prefer a steel frame for durability
- You need a 21-inch cutting width for faster mowing
- You want a self-propelled mower for large lawns
- You are looking for a standard push mower
Verdict: ZeHuoGe 16-Inch Gas Scarifier is a specialized tool for users who need to dethatch and scarify their lawn with a powerful 7 HP engine and a large 13.2-gallon bag.
PowerSmart 21-Inch 144cc Gas Push Mower
Best for: Flat lawns needing a wide 21-inch cut
- Engine Stroke
- 4-Stroke
- Cutting Width
- 21 inch
- Drive Type
- Push
- Mowing Functions
- 2-in-1 (side-discharge, mulching)
- Motor Type
- 144cc 4-Stroke OHV
- Height Adjustments
- 6 positions, 1.5" to 3.9"
The PowerSmart 21-inch push mower features a 144cc 4-stroke OHV engine with forced air cooling. It offers a 21-inch cutting deck and six height positions ranging from 1.5 to 3.9 inches. The unit supports side-discharge and mulching. Weighing 44 pounds, it includes 10-inch rear wheels for smooth movement. This model suits users who need a reliable, easy-to-assemble push mower for moderate-sized yards.
- 144cc 4-stroke OHV engine with forced air cooling
- 21-inch cutting deck for wider mowing paths
- Six height adjustment positions from 1.5 to 3.9 inches
- 95% pre-assembled for quick setup
- 144cc engine displacement is lower than the 170cc and 212cc engines in other options
- Push drive type requires more effort than self-propelled models
- 44-pound weight is higher than lighter alternatives
- You prefer a push mower for smaller or flat lawns
- You want a 21-inch cutting width for efficiency
- You need easy assembly with minimal tools
- You require self-propelled drive for hilly terrain
- You need an engine larger than 144cc
- You want mulching and side-discharge plus bagging
Verdict: PowerSmart 21-Inch 144cc Push Mower fits users who value a wide cutting deck and easy setup over self-propelled convenience. It is a solid choice for flat yards where manual pushing is manageable.
Specifications side by side
| Spec | PowerSmart 21-Inch 170cc Self-Propelled Gas Mower | PowerSmart 21-Inch 140cc Gas Push Mower | Sang Seiyoga 16-Inch Gas Scarifier | ALYIAMXL 16in Gas 2-in-1 Dethatcher | ZeHuoGe 16-Inch Gas Scarifier | PowerSmart 21-Inch 144cc Gas Push Mower |
|---|---|---|---|---|---|---|
| Cutting Width | 21 in | 21" | – | – | – | 21 inch |
| Drive Type | Self-propelled (rear-wheel drive) | Push | – | – | – | Push |
| Mowing Functions | 3-in-1 (mulch, side discharge, bag) | 3-in-1 (discharge, bagging, mulching) | – | – | – | 2-in-1 (side-discharge, mulching) |
| Motor Type | 4-stroke OHV, 170 cc | 140cc Briggs&Stratton 4-stroke | 4-stroke gasoline | 4-stroke gasoline | 4-stroke gasoline | 144cc 4-Stroke OHV |
| Height Adjustments | 6 positions (1.5" – 3.9") | 6 adjustments (1.5 to 3.9 inches) | 5-step, -0.6in to +0.6in | – | 5-position, -0.6 in to +0.6 in | 6 positions, 1.5" to 3.9" |
| Power Type | Gas | Gas | – | Gas | Gas | Gas |
| Engine Displacement | 170cc | 140cc | 212cc | 212cc | 212cc | 144cc |
| Engine Power | – | – | 7 HP | – | 7 HP | – |
| Engine Stroke | 4-Stroke | 4-Stroke | 4-Stroke | 4-Stroke | 4-Stroke | 4-Stroke |
| Collection Bag Capacity | – | – | 13.2 Gallon | 13.2 Gallon | 13.2 Gallon | – |
| Dimensions | 56.5 × 22 × 42.5 inches | 32.9 × 16.5 × 22.6 inches | 51 × 22 × 43 inches | 22 × 51 × 43 inches | 22 × 51 × 43 inches | 33 × 23 × 18 inches |
| Weight | 59 pounds | – | 85 pounds | 85 pounds | 85 pounds | 44 pounds |
| Size | 21 Inch-170cc | – | – | 16 IN | – | – |
| Color | Black | Black | Green | Black | Green | gas |
| Model | DB8621S | B8621P | 0 | Lawn Sweeper | ZHG-P480451 | DB2321CR |
How we picked these mowers
We selected these lawn mowers by scanning Amazon listings for the Engine Stroke specification. We only included products that explicitly state they use a 4-Stroke engine in their title or feature list. This ensures you get a clear, consistent comparison of engines that do not require oil mixing.
The products are ordered by availability first, then by the listing's overall rating weighted by review count. We also considered how well the specs meet our guide criteria. All details come from published specifications. We did not handle these units or test them. Prices and stock status are shown live on the page and refresh daily.
Key Specs for Choosing Your Mower
Check Engine Displacement
Engine displacement indicates the power available for cutting. Larger cc values generally handle thicker grass better. The top pick offers a 170cc engine for reliable performance on uneven terrain. Budget options may feature smaller engines like 140cc or 144cc, which are sufficient for flat, small lawns. Specialized scarifiers often use 212cc engines to manage heavy debris. You should match the cc rating to your grass density and lawn size to ensure consistent cutting without stalling.
Select Drive Type
Drive type determines how the mower moves. Self-propelled models reduce effort on slopes or large areas. The best overall choice uses rear-wheel drive for traction on uneven ground. Push mowers require you to walk behind them, making them lighter and easier to store. This option suits flat yards where manual pushing is manageable. Consider your physical ability and lawn slope when choosing between self-propelled and push designs for your specific needs.
Review Cutting Width
Cutting width affects how many passes you need. A 21-inch deck covers more ground per pass than a 16-inch deck. Most standard mowers in this list feature a 21-inch width for efficient lawn care. Narrower 16-inch models appear in specialized scarifiers and dethatchers. These are designed for precise aeration rather than broad mowing. Choose a wider deck for speed on open lawns, or a narrower one for tight spaces and specialized maintenance tasks.
Compare Mowing Functions
Mowing functions define how clippings are handled. Three-in-one models offer bagging, mulching, and side discharge options. The budget pick includes these versatile functions for small lawns. Some models provide two-in-one capabilities, focusing on bagging and mulching. Specialized scarifiers may only support bagging for debris removal. Check the function list to ensure the mower matches your preferred disposal method and lawn care routine without needing extra attachments.
Consider Collection Capacity
Collection bag capacity determines how often you empty the mower. Standard mowers often lack large integrated bags. Specialized scarifiers include substantial 13.2-gallon bags to handle thatch and debris. This large capacity reduces interruptions during dethatching tasks. For standard mowing, you may need to check bags more frequently. Ensure the bag size matches your maintenance frequency and the volume of debris you expect to remove from your lawn.
Frequently asked questions
Which 4-Stroke mower is best for slopes?
The PowerSmart 21-Inch 170cc Self-Propelled Gas Mower is the top choice for uneven terrain. Its self-propelled drive type and 170cc engine provide reliable traction. The steel deck adds stability, making it easier to manage on slopes compared to push models.
What is the lightest 4-Stroke mower in this list?
The PowerSmart 21-Inch 144cc Gas Push Mower is the lightest option at 44 pounds. It measures 33 inches long, making it easy to store and maneuver. This lightweight design suits flat lawns where you do not need self-propelled assistance.
Do any of these mowers include a large collection bag?
Yes, the specialized dethatchers include a 13.2-gallon collection bag. The Sang Seiyoga, ALYIAMXL, and ZeHuoGe models all feature this high-capacity bag. It is designed to handle the heavy debris generated during scarifying and dethatching tasks effectively.
Which model has the most powerful engine?
The Sang Seiyoga, ALYIAMXL, and ZeHuoGe scarifiers all have the highest power. They feature a 212cc engine displacement and produce 7 HP. This power is necessary for the demanding work of dethatching and aerating compacted soil.
Can I mulch with a 4-Stroke push mower?
Yes, the PowerSmart 21-Inch 140cc Gas Push Mower supports mulching. It offers a 3-in-1 mowing function that includes mulching and side discharge. This versatility allows you to recycle grass clippings or bag them for small, flat lawns.
What is the widest cutting deck available?
The widest cutting deck is 21 inches. This width is available on the PowerSmart 170cc, 140cc, and 144cc models. A wider deck covers more ground per pass, which helps you finish mowing larger flat areas more quickly.
