Lawn Mower Won't Start After Sitting — Here's Why

It's a story we hear constantly in Central Florida: the lawn mower sat in the garage all winter (or even just a few weeks), and now it won't start. You pull the cord a dozen times, nothing. This is one of the most common small engine problems in Florida — and it's almost always caused by the same thing.

The #1 Reason: Old Ethanol Gas

Regular pump gas contains ethanol, which starts degrading in as little as 30 days. In Florida's humidity, that process happens even faster. Old gas leaves a sticky varnish inside the fuel system that clogs carburetors, fuel filters, and fuel lines. The engine cranks but can't get fuel, so it won't start.

Signs Old Gas Is the Problem

• Engine cranks normally but never fires
• Starts briefly then immediately dies
• Smell of sour or stale fuel from the tank
• Visible discoloration or sediment in old gas
• Fuel isn't reaching the carburetor

The Fix — What We Do on a Service Call

When we show up to a no-start mower in Central Florida, here's our process:

• Drain old gas completely — don't try to mix it with fresh gas
• Clean or flush the fuel lines — varnish buildup restricts flow
• Replace the fuel filter — cheap part, often completely clogged
• Clean the carburetor — disassemble and clean jets and passages
• Replace spark plug — if fouled from repeated failed starts
• Refill with fresh ethanol-free gas — the only gas we recommend for small engines

How to Prevent It Next Time

• Always use ethanol-free gas in small engines
• Add fuel stabilizer if storing for more than 30 days
• Run the engine until the carb is dry before long storage
• Change the fuel filter every season

We Come to You in Central Florida

Don't haul your mower anywhere. We come to Clermont, Winter Garden, Ocoee, Windermere, Horizon West, Minneola, and surrounding areas. Call or text (321) 430-5999.