Generator Won't Start After Storage — Common Causes to Check
Generators sit for months between power outages. That long storage period is exactly when problems develop. The good news: the causes are predictable and most are fixable without major expense.
Old Fuel Is the Most Likely Cause
Generators are the piece of equipment most likely to be started under urgent conditions — when power goes out — after sitting the longest. Ethanol-blend gasoline degrades in 30 to 60 days. After six months in the tank, it leaves a sticky varnish residue in the carburetor that blocks fuel flow. The generator cranks fine but will not fire, or fires briefly and immediately dies. Draining the old fuel and cleaning the carburetor solves this in most cases.
Choke and Starting Sequence
Generators often get started incorrectly, especially by people who use them infrequently. Most require the fuel valve to be on, the choke fully closed, and sometimes a primer bulb pressed several times before pulling. Skipping any step can make a perfectly good generator appear broken. Review the starting procedure in the owner's manual — but if it still will not start after correct procedure, move on to inspection.
Oil Level Shutdown
Most modern generators have a low-oil shutdown sensor that prevents the engine from running when oil is low. If oil has leaked or evaporated during storage — which can happen — the sensor cuts power before the engine can run. Check the oil level first. If low, add the correct oil and try again. If oil is full but the sensor is faulty, it can falsely prevent starting even with adequate oil.
Spark Plug and Ignition
A fouled or corroded spark plug is a common cause of no-start after storage. Remove the plug, inspect it — a dark, sooty plug indicates rich running; a white or blistered electrode means lean. Gap the plug or replace it. Also check that the spark plug wire is firmly seated — vibration from years of use can loosen it.
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