Nothing’s more frustrating than getting ready to mow—only to find your lawnmower just won’t start. Whether you have a gas, battery, or electric mower, you don’t need to be a mechanic to solve most no-start problems. With this easy-to-follow guide, you’ll learn how to fix a stubborn mower and get your yard back on track. Let’s break down the most common causes and real fixes for every type of mower.
Quick-Check: Common Reasons Lawnmowers Won’t Start
- Empty fuel tank or old, stale gasoline (gas mowers)
- Dead battery or loose connection (battery/electric start mowers)
- Spark plug is fouled, dirty, or disconnected (gas mowers)
- Clogged air filter or fuel filter
- Flooded carburetor (gas models)
- Tripped breaker or faulty extension cord (electric mowers)
- Safety switches or control levers not fully engaged
- Jammed or stuck blade—grass, sticks, or debris under deck
- Loose, broken, or corroded wires (all types)
Step 1: Fuel or Power Check
- Gas mower: Open the fuel cap and check the tank. Old or stale gas? Drain and replace with fresh fuel. Water or debris in the tank? Clean out before refilling.
- Battery mower: Charge the battery fully. Make sure it’s clicked into place, with no corrosion or dirt on the contacts. Try a second battery if you have one.
- Electric/corded mower: Plug in a lamp or charger to confirm the outlet works. Use only heavy-duty outdoor cords with no damage.
Step 2: Spark Plug, Air Filter, and Fuel Filter (Gas Mowers)
- Remove the spark plug wire, pull the plug, and check for soot, oil, or cracks. Clean with a wire brush or replace with a new one.
- Set the spark plug gap to your mower’s specs (usually 0.028–0.030 in).
- Replace dirty or wet air filters—if clogged, your mower can’t “breathe” and won’t start.
- Check the fuel filter. Replace if it looks dirty, or fuel won’t flow freely.
Step 3: Carburetor and Flooding Fixes (Gas Mowers)
- Prime the engine or set the choke, then pull the starter. If you smell gas or the spark plug is wet, the engine may be flooded. Let it sit 15 minutes, then start with choke off.
- If the mower fires only with starting fluid, clean the carburetor. Remove and spray with carb cleaner. If needed, rebuild or replace it.
- Make sure the primer bulb works and isn’t cracked.
Step 4: Safety Switches, Levers, and Cables
- All mowers have safety switches—blade, seat, bail lever, or key. Make sure all are fully engaged. If a lever feels loose, the cable might be stretched or disconnected.
- Wiggle levers and pedals if stuck. Spray a little lubricant if they’re stiff after winter.
- Check wires and cables for signs of rodent damage, especially after storage.
Step 5: Battery, Cord, and Electrical Issues (Battery/Electric Mowers)
- Ensure battery is charged, installed firmly, and contacts are clean. Try a known-good battery if possible.
- For electric/corded mowers, use a heavy-duty cord and check for frays, cuts, or burn marks. Test another outlet if unsure.
- Reset GFCI outlets or circuit breakers if tripped. Replace blown fuses.
Step 6: Blade, Deck, and Obstruction Checks
- Disconnect the spark plug wire or remove the battery. Tip the mower safely and look under the deck for grass, string, or sticks jamming the blade or flywheel.
- Spin the blade by hand (wear gloves)—it should turn smoothly. Remove any clogs and debris.
- Check for bent blades or other damage from hitting an object last season.
Step 7: Advanced Troubleshooting (If Still Won’t Start)
- Gas: Test the ignition coil with a spark tester. Replace if you get no spark with a new plug.
- Battery: Try your mower’s battery in another compatible tool. If it won’t work there either, replace the battery.
- Electric: If everything checks out but the mower is dead, the power switch, wiring, or internal control board may need replacement.
- If engine turns but won’t start, double-check fuel, spark, and air. If it won’t crank at all, suspect starter, solenoid, or deeper engine problems—consider professional help.
Step-by-Step Fixes for Most Mower Types
- Replace spark plug, air filter, and fuel filter every season
- Drain old fuel before winter and use stabilizer
- Charge batteries monthly in winter; store in a dry, warm place
- Lubricate control cables, levers, and wheels every spring
- Keep deck clean and clear after each mow to prevent jams
- Inspect wires and connectors for corrosion, loose spots, or breaks
Frequently Asked Questions (FAQ)
What’s the first thing to check if my mower won’t start?
Check the fuel (gas mowers) or battery (electric). Old, stale fuel and dead batteries are by far the most common causes.
Can a dirty air filter stop my mower from starting?
Absolutely. A clogged air filter blocks airflow, making starting very difficult. Replace it at least once per year.
Why does my mower click but not turn over?
For battery or electric models, check the battery charge, connections, and starter switch. For gas, check safety switches and that the engine isn’t jammed.
Should I use starter fluid if my mower won’t start?
A brief spray can help diagnose fuel issues. If it fires with fluid but dies, you likely need carburetor cleaning or repair.
When should I call a professional?
If you’ve tried these steps and your mower still won’t start, or if you suspect engine or electrical damage, a repair shop can help with advanced diagnostics.
Conclusion: Get Your Mower Running Again—The Easy Way
Most lawnmower no-start problems are caused by old fuel, dirty plugs, dead batteries, clogs, or safety switches—simple things you can check and fix yourself. With a little routine maintenance and this step-by-step guide, you’ll have your mower starting easily for years to come. Don’t let a stubborn mower stop your mowing plans—fix it fast and get your yard looking great!
Tip: Bookmark this guide for next season and keep your mower happy with regular cleaning and care!