On this page
On a storm night, a generator that sat untouched since the last outage either starts or it does not, and power generator maintenance decides which outcome you get. A machine that gets fresh fuel, clean oil, a fresh spark plug and a look over its cord ends starts when the lights go out. Fuel generators run outdoors only, far from doors and windows, because of carbon monoxide. The checklist below works through those jobs in order, with no part left to guesswork at the moment you need the machine.
SolarKitHQ earns a commission when you buy through links on this page, at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Affiliate disclosure.
Power generator maintenance: the quick answer
Work through fuel, oil, air, spark and cord ends, in that order, and do it before the season you need the machine, not during an outage. Drain stale fuel and refill with fresh fuel, change the oil, clean or replace the air filter, fit a fresh spark plug, and check the cord ends for cracks, loose prongs and heat marks. Keep the manual with the generator, and match the oil, the plug and the parts to what the manual gives. Run the machine through its checks on a calm day, so a fault shows up before the storm, not during it. A machine kept this way starts when you need it.
Keep the fuel fresh
Fuel goes stale in storage, and stale fuel clogs the carburetor jets. Drain the tank and the carburetor bowl before the generator sits unused, and refill with fresh fuel when the machine goes back to work. A fuel stabilizer keeps fresh fuel usable through storage; the fuel stabilizer guide explains how to use it. Work in a well-ventilated area and wear work gloves while you handle fuel and carburetor parts. See the how to remove gas from a generator guide for the draining steps.
If the generator already smells of stale fuel, drain it before you try to start the machine. Fresh fuel in a dirty carburetor still leaves the jets clogged, so clean the carburetor after the drain. The gas generator repair guide covers the cleaning steps.
Change the oil and the air filter
Oil collects grit and moisture as the engine runs, and a dirty air filter chokes the air the engine needs. Change the oil on the schedule the manual gives, and clean or replace the air filter at the same time. Check the oil level before each use, and top it up with the oil grade the manual names. Wipe the filler cap and the dipstick clean before you check the level, so grit stays out of the engine. See the generator oil weight guide to match the oil to the season.
Mind the spark plug and the battery
A fouled spark plug gives a weak spark or no spark, and the engine cranks without catching. Pull the plug, look at the electrode and the insulator, and fit a fresh plug if the old plug is black, wet or cracked. Keep a spare plug with the generator, matched to the plug the manual names. If the generator has a starter battery, keep it charged and check its terminals for corrosion; a battery that sat flat through storage may need a charge before the machine will crank. See the how to charge a generator battery guide.
Check the cord ends and the outlets
A generator that runs but powers nothing often has a fault at the cord end, not in the engine. Look over the plug ends for cracks, loose prongs, heat marks and a cord grip that no longer holds the cord. Match any replacement plug end to the outlet it serves, and check the outlets on the generator panel for damage and a firm fit. Anything that ties into home wiring should go to a licensed electrician. See the types of generator plugs guide to match the plug to the outlet.
Store it ready for the next outage
Storage is where most generator faults start, so put the machine away ready to run. Drain the fuel or fill the tank with stabilized fuel, change the oil, and cover the generator against dust and damp. Store the generator where it stays dry and where you can reach it in an outage, and keep the fuel can beside it, sealed and out of the way. Keep the manual, a spare spark plug and the part numbers with the machine, so nothing has to be hunted down in an outage. Run the generator now and then through the off season, so a fault shows up on a calm day rather than in a storm.
Ways to keep a generator ready
- Keep fresh fuel in the tank, and drain it before long storage.
- Change the oil and clean the air filter on the schedule the manual gives.
- Keep a spare spark plug matched to the manual with the generator.
- Check the cord ends for cracks and a firm cord grip before each use.
- Keep the manual with the machine, so the part numbers stay at hand.
FAQ: power away from the grid
How often should I service a portable generator?
Service it before the season you need it, and again when it shows signs of trouble: hard starting, rough running or a smell of stale fuel. The manual gives the service schedule for your model, so follow what it says.
What happens if I leave fuel in the generator?
Fuel goes stale in storage and clogs the carburetor jets, so the engine runs rough or will not start. Drain the tank and the carburetor bowl before storage, or fill the tank with stabilized fuel.
Why does my generator start and then stop?
Stale fuel and a clogged carburetor jet cause a generator to start and then stop. Drain the tank and the carburetor bowl, refill with fresh fuel, and clean the carburetor jets. If the fault stays, check the spark plug before you order parts.
Do I need fuel stabilizer?
Stabilizer keeps fresh fuel usable through storage, so use it when the generator will sit unused. The fuel stabilizer guide explains how to use it and when to add it.
Can I do generator maintenance myself?
Routine service covers fuel, oil, the air filter, the spark plug and the cord ends, and the manual walks through each job. Internal engine work sits beyond routine service, and a licensed technician should take over from there.
Related solar guides
See the how to start a portable generator, the portable generator troubleshooting guide, the gas generator repair guide and the propane generator maintenance checklist.
