Lawn Mower Won't Start

Lawn mower won't start? Learn causes, DIY fixes, and repair costs ($30–$200). Step-by-step troubleshooting guide.

Typical repair cost: $30–$200 · DIY difficulty: Moderate · About 20–45 minutes.

What usually causes it

• Stale fuel
• Dirty air filter
• Fouled spark plug
• Dead battery (electric start)
• Clogged carburetor
• Safety switch engaged

What you need

• Spark plug wrench
• Fresh fuel
• Air filter
• Spark plug

How to fix it yourself

1. Check fuel — if it's been sitting for over 30 days, drain and add fresh fuel
2. Check the air filter — remove, clean, or replace if dirty or clogged
3. Remove and inspect the spark plug — replace if fouled, corroded, or gapped incorrectly
4. For electric start: charge or replace the battery
5. Clean or spray carburetor cleaner into the air intake
6. Check that the safety bail/handle lever is fully engaged when pulling the cord

When to call a pro

If fresh fuel, a new spark plug, and a clean air filter don't work — the carburetor likely needs professional cleaning or rebuilding.

Get a fixed price from a local pro