Symptoms
- Pull cord resists or engine won't fire
- Engine floods with gas smell
- Starts and immediately stalls
- Hasn't run since last season
Likely causes
- CommonStale fuelOld gas loses volatility and gums the carburetor.
- CommonDirty air filterA clogged filter starves the engine of air needed to start.
- CommonFouled spark plugCarbon buildup prevents a reliable spark.
- PossibleFlooded engine from over-primingToo many primer presses can flood the cylinder with fuel.
- PossibleClogged carburetorVarnish deposits from old fuel block small passages.
What to do
- Drain old fuel and refill with fresh gasoline if it sat over winter.
- Remove and inspect the air filter; clean foam filters or replace paper ones if dirty.
- Pull and check the spark plug for fouling; clean or replace it.
- If flooded, hold the throttle wide open and pull the cord several times without choking.
- Check the fuel line for cracks or blockages between the tank and carburetor.
- Verify the on/off switch and kill switch are in the run position.
- If it still won't start after these steps, the carburetor likely needs professional cleaning.
Tools and parts
- Spark plug socket
- Fresh gasoline
- Replacement air filter
Small engine air filterSearch: “tiller air filter replacement”
Spark plugSearch: “rototiller spark plug”
When to call a pro
A small-engine shop can clean or rebuild the carburetor if basic maintenance doesn't get it running.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.