By Graham FisherUpdated November 2026
A yard machine lawn mower 20 inch won’t start for a handful of predictable reasons: a worn recoil starter, a weak or dead battery, a clogged carburetor, or a spark plug that has fouled. Before buying anything, it helps to know which of those failures you are dealing with. The picks below focus on the most common replacement parts and tools a homeowner might need, compared by the job they do, the specs they state, and the kind of owner each one suits. Selection was based on published specifications, brand reputation and recurring owner feedback patterns, not on hands-on testing.
Our top picks at a glance
- 1
TOP CHOICEBest overallRecoil Pull Starter Assembly – Compatible for MTD/Huskee/Yard MachinesView on Amazon - 2
Best for quiet, fume-free mowingGreenworks 40V 16in Push Lawn Mower, 4.0 Ah Battery and ChargerView on Amazon - 3
Best for a larger battery-powered yardGreenworks 48V (24V x 2) 20in Push Lawn Mower, (2) 4.0 Ah Batteries KitView on Amazon - 4
Best budget pick for a self-propelled replacementBILT HARD 21" Self Propelled Gas Lawn Mower – 201cc 4-Cycle OHV, 3-in-View on Amazon
Our Top Picks
Quick Comparison
| Product | Best for | Key feature |
|---|---|---|
| Recoil Pull Starter Assembly – Compatible for MTD/Huskee/Yard Machines 139cc Push Lawn Mowers (Model SKU01) | Gas mowers that will not spin over on the pull cord | Direct replacement starter for MTD/Yard Machines-style 139cc engines |
| Greenworks 40V 16in Push Lawn Mower, 4.0 Ah Battery and Charger | Small, quiet, fume-free yards | Push-button start with no pull cord |
| Greenworks 48V (24V x 2) 20in Push Lawn Mower, (2) 4.0 Ah Batteries Kit | Larger yards that need more runtime | Brushless motor with dual-battery system and LED headlight |
| BILT HARD 21″ Self Propelled Gas Lawn Mower | Owners replacing a gas mower on a tighter budget | 201cc 4-cycle OHV engine with 3-in-1 discharge options |
Recoil Pull Starter Assembly – Compatible for MTD/Huskee/Yard Machines 139cc Push Lawn Mowers (Model SKU01)
Recoil Pull Starter Assembly – Compatible for MTD/Huskee/Yard Machines 139cc Push Lawn Mowers (Model SKU01)
Best for: Gas push mowers where the pull cord is frayed, the rope will not retract, or the starter pawls no longer engage the flywheel.
This is the right first purchase for owners whose yard machine lawn mower 20 inch won’t start because the engine turns over only slightly, or the cord pulls freely without the engine catching. Many Yard Machines and MTD-family push mowers use a similar 139cc layout, so the part is aimed at that group.
Key specs
- Designed as a replacement recoil starter assembly
- Listed compatibility: MTD, Huskee and Yard Machines 139cc push mowers
- Model reference: SKU01
Pros
- Addresses one of the most common no-start causes on pull-start mowers
- Replacement is usually a bolt-on job with basic hand tools
- Restores the original starting method without changing the engine
Cons
- Only useful if the starter is the actual fault; it will not fix fuel or spark problems
- Fit should be confirmed against the engine model before ordering
Bottom line: The best choice for owners of a pull-start Yard Machines-style mower who have already ruled out fuel and spark issues.
Greenworks 40V 16in Push Lawn Mower, 4.0 Ah Battery and Charger
GreenworksQuiet walk-behind mower with push-button start; gas-free operation eliminates fumes and pull starts 40V 16in Push Lawn Mower, 4.0 Ah Battery and Charger
Best for: Quiet, fume-free mowing on small to medium lots, and owners who want to skip the pull cord entirely.
If the old gas mower keeps refusing to start and you are willing to switch power sources, a battery walk-behind removes the whole category of carburetor, fuel and recoil problems. It suits smaller lots and owners who mow close to the house.
Key specs
- 16-inch cutting width
- 40V battery platform with 4.0 Ah battery and charger included
- Push-button start, no pull cord
Pros
- No gasoline, oil changes or spark plugs to maintain
- Push-button start removes the most common frustration of gas mowers
- Quiet and low-vibration operation, which owners often mention
Cons
- Runtime is limited on larger lots without a spare battery
- A 16-inch deck takes longer on big areas than a 20-inch or 21-inch deck
Bottom line: A good fit for small, quiet yards where the owner would rather replace the gas engine than keep chasing its starting problems.
Greenworks 48V (24V x 2) 20in Push Lawn Mower, (2) 4.0 Ah Batteries Kit
Brushless motor with LED headlight and dual port rapid charger, push-button start for easy lawn care. Greenworks 48V (24V x 2) 20in Push Lawn Mower, (2) 4.0 Ah Batteries Kit
Best for: Medium to larger yards that need a 20-inch cutting width and more runtime than a single-battery mower provides.
This is the closest like-for-like swap for a 20-inch gas push mower. It uses two batteries, so owners can mow longer before recharging. It is a practical option if the gas mower is no longer worth repairing.
Key specs
- 20-inch cutting width
- 48V system built from two 24V packs
- Two 4.0 Ah batteries included
- Brushless motor, LED headlight, dual-port rapid charger
Pros
- Matches the cutting width of a 20-inch gas mower
- Brushless motor is generally associated with longer motor life
- Dual-port charger lets owners top up both batteries at once
Cons
- Two batteries and a charger add weight and storage space
- Battery replacement later will be an added expense to plan for
Bottom line: The strongest option for owners who want a 20-inch cut and enough battery capacity to finish a mid-sized yard in one session.
BILT HARD 21″ Self Propelled Gas Lawn Mower – 201cc 4-Cycle OHV, 3-in-1 Bagging/Mulching/Side Discharge, 8 Adjustable Cutting Heights & Smooth Easy Start
BILT HARD 21" Self Propelled Gas Lawn Mower – 201cc 4-Cycle OHV, 3-in-1 Bagging/Mulching/Side Discharge, 8 Adjustable Cutting Heights & Smooth Easy Start
Best for: Owners who want to stay with a gas mower but replace an aging 20-inch unit with a self-propelled model.
Someone who has decided that the old mower is not worth reviving may prefer a new gas machine. This one uses a 201cc engine and offers bagging, mulching and side discharge, so it covers most typical lawn tasks.
Key specs
- 21-inch cutting deck
- 201cc 4-cycle OHV engine
- Self-propelled drive
- 3-in-1 bagging, mulching and side discharge
- 8 adjustable cutting heights
Pros
- Self-propelled drive reduces fatigue on slopes and larger lawns
- Three discharge modes cover most cleanup needs
- Eight height settings suit a range of grass types
Cons
- Gas engine still needs regular oil, fuel and spark plug maintenance
- Heavier than battery models, which can make storage and lifting harder
Bottom line: A practical replacement for owners who prefer gasoline power and want self-propulsion in a single new machine.
Buying Guide
Decide whether to repair or replace
If the engine is only failing to start, a repair part such as a starter or spark plug is usually more economical than a new mower. If the deck is cracked, the engine has internal damage, or repairs would cost more than the mower is worth, replacement makes more sense.
Good picks for this: Recoil Pull Starter Assembly; BILT HARD 21″ Self Propelled Gas Lawn Mower
Match the cutting width to the yard
A 20-inch deck is a common width for mid-sized lawns. Smaller deck widths mean more passes on the same area. Confirm the deck width you actually need before you buy a replacement.
Good picks for this: Greenworks 48V 20in Push Lawn Mower; Greenworks 40V 16in Push Lawn Mower
Check starting method
Pull-start mowers depend on the recoil starter and a healthy compression stroke. Push-button and electric start models remove the cord entirely. Choose based on whether you want to keep a gas engine or switch power sources.
Good picks for this: Recoil Pull Starter Assembly; Greenworks 40V 16in Push Lawn Mower
Consider battery capacity and runtime
Battery mowers are rated in amp-hours, and runtime depends on grass height, lawn size and deck width. Two-battery systems extend runtime without a recharge in the middle of the job.
Good picks for this: Greenworks 48V 20in Push Lawn Mower; Greenworks 40V 16in Push Lawn Mower
Look at engine size and type
For gas mowers, engine displacement in cc and engine design (such as 4-cycle OHV) affect torque and maintenance. Confirm that any replacement part matches your exact engine model number.
Good picks for this: BILT HARD 21″ Self Propelled Gas Lawn Mower; Recoil Pull Starter Assembly
Evaluate drive and self-propulsion
Self-propelled drive helps on slopes and long lawns. Push models are lighter and cheaper to store. Think about terrain and how much pushing you are willing to do.
Good picks for this: BILT HARD 21″ Self Propelled Gas Lawn Mower; Greenworks 40V 16in Push Lawn Mower
Plan for durability and care
Gas mowers need fresh fuel, clean air filters and sharp blades. Battery mowers need proper charging and storage, usually indoors and away from extreme heat or cold. Routine care prevents most no-start problems.
Good picks for this: Recoil Pull Starter Assembly; Greenworks 48V 20in Push Lawn Mower
FAQ
Why won’t my yard machine lawn mower 20 inch start even though it has fresh gas?
Fresh fuel rules out only one cause. Check the spark plug for fouling or a missing spark, clean or replace the air filter, and confirm the carburetor is not gummed up from old fuel. A failed recoil starter can also prevent the engine from turning over at all.
Is a recoil starter replacement difficult to do myself?
Most homeowners can replace a recoil starter with basic hand tools by following the engine manual. Disconnect the spark plug wire first and work on a stable surface. If you are unsure about the fit or the procedure, a small engine repair shop can do the job.
How do I know if the battery is the problem on a battery mower?
Check whether the battery is charged and seated correctly, and look for any error indicators on the battery or charger. If the battery will not hold a charge after a full cycle, it likely needs replacement.
Does old gasoline really cause a yard machine to not start?
Yes. Gasoline that has sat for several months can form varnish that clogs the carburetor jets. Owners often report that draining the old fuel or running the mower dry before storage prevents this.
Should I replace the spark plug first?
A spark plug is inexpensive and a common cause of hard starting, so it is a reasonable early check. Remove it, inspect the electrode, and replace it if it is fouled or worn, using the plug specified in the owner’s manual.
Is a battery mower better than a gas mower for a 20-inch deck?
It depends on your yard and priorities. Battery models avoid fuel and engine maintenance and start with a button, while gas models offer longer runtime without recharging. Compare the runtime you need with the battery capacity offered.
Conclusion
When a yard machine lawn mower 20 inch won’t start, the right fix depends on the cause. A worn recoil starter makes the Recoil Pull Starter Assembly the logical first purchase for pull-start owners. Those who want to switch to battery power have two strong options: the Greenworks 40V 16in for smaller, quiet yards, and the Greenworks 48V 20in for a 20-inch cut with more runtime. Owners who want to stay with gasoline and self-propulsion may prefer the BILT HARD 21″ Self Propelled Gas Lawn Mower. Confirm your engine model, battery needs and yard size before buying.
Sources
- Consumer safety guidance on lawn mower operation, maintenance and storage (cpsc.gov)
- Information on battery technology and efficient outdoor power equipment (energy.gov)
- Research-based guidance on lawn care, mower maintenance and turf management (extension.org)
Related reading
- Yard Machines Lawn Mower Won't Start: 7 Causes and Fixes
- Yard Machine Riding Lawn Mower Won't Start: 7 Causes and Fixes
- Yardman Riding Lawn Mower Won't Start: 7 Causes and Fixes
- Yardman Lawn Mower Won't Start: 8 Causes and Fixes (2026)
- Worx Battery Lawn Mower Won't Start: 8 Causes and Fixes
About Graham Fisher
Graham Fisher is part of our editorial team and reviews and edits our lawn mowers guides, checking product details against manufacturer specifications and owner feedback.
