Generator Care Generator Maintenance

8 Tips to Maintain & Service Your Portable Generator

Tips to Maintain & Service Your Portable Generator

In the modern world, portable generators are a necessity for many people. Whether you use portable generators for recreation or power your home during a power outage, they are important to stay in good condition. And like any other generator out there, they do need regular and periodic maintenance.

You want to give them the best maintenance to maintain their optimal performance at all times. It’s also an excellent way to deal with expensive repairs and replacements that you can get away with when you maintain your unit. Here is a list of essential portable generator maintenance tips you can employ.

1. Inspect and Clean the Spark Plugs

Even though it’s rare for the spark plugs to develop issues, it’d be best to inspect and clean them regularly for reliable spark production. All you need is the right spark plug socket for your generator.

Start by removing the spark plug cable and use the spark plug socket to remove the plug for the generator engine.

Inspect its electrode; what you’re checking is a clean plug tip with no worn-out sign. If there are any, it would mean the plug might not produce enough sparks required for reliable ignition.

Spark Plug

Don’t forget to check for the spark plug gap. Get a gapping tool and refer to your generator manual for the ideal gap size for your model.

If the plug is too dirty (covered with carbon deposits) or it has some worn-out signs, replace it with the compatible replacement. Refer to your generator manual for the recommended spark plug.

Thread it carefully into the engine and use the spark plug tool to install it firmly. Don’t forget to attach the spark plug wire by wearing the rubber boot right.

2. Change the Engine Oil

Engine oil plays a crucial role in ensuring your portable generator maintains its optimal performance for an extended period. It’s responsible for lubricating the moving parts in the generator engine, collect any dirt accumulating inside the crankcase, and help transfer heat to the crankcase.

So, with time, the engine oil gets so light and dirty that it doesn’t fulfill its primary purpose of lubricating the metals parts, or neither does it help with the heat transfer or engine cleansing.

Engine Oil

Besides this, the engine oil reduces, exposing the generator to catastrophic failure. So, you must check the oil level regularly and change it when dirty or thin.

Check the oil level by making sure it’s at the full mark on the dipstick. You want to make sure the generator is on a level surface.

How to Change Engine Oil:

  • When it comes to changing the oil, you want to do it when it’s warm and the generator is on an evenly flat surface.
  • Run the generator for some minutes to warm up the engine and allow it to cool down slightly.
  • With the generator on a level surface, place a draining pot beneath the drain plug and use the ideal oil drain plug socket or wrench size to start draining the oil out.
  • Allow the oil to drain completely to the last drop before adding the new oil. Avoid overfilling as that could lead to other issues like the engine burning oil. Dispose of the used oil properly – through the approved waste management facility will be the best.
  • Refer to your generator manual for the type of oil to use – you want to ensure you’re getting the ideal oil grade for your model and the operating environment. Also, check how much you need. If not available, you can estimate the amount with the amount of used oil you drained.
  • Once you add the oil, visually check the oil level – you want it around 1-2 threads of the fill hole. If you use the dipstick to check the level, AVOID screwing it in.

3.Clean or Change the Air Filter

Air filters are one of the most neglected parts of a generator, even though they play a huge role in optimally ensuring the unit runs. It cleans the air that enters the carburetor to be mixed with fuel.

When compromised, dirt and debris might find their way into the carburetor, blocking the small passageways and jets that control fuel flow inside it.

Air Filter

If that were to happen, the engine wouldn’t get enough fuel, running lean. The opposite could happen if the air filter cartridge were to get clogged by all the dirt and debris it collects – it will run rich, more fuel, and less air.

So, you want to make it your maintenance responsibility to clean and change the air filter regularly. It’s quite easy. The air filter cartridge or foam is relatively cheap.

How to Clean the Air Filter:

  • Start by removing the snaps or bolts holding the cover to the air filter assembly.
  • Remove the cartridge or foam element, whichever your model uses.
  • Mix some liquid dishwasher detergent in water and keep it in. Give it some minutes to soak before washing it.
  • Rinse it in clean water and squeeze it thoroughly in a clean water-absorbing cloth to dry it.
  • Saturate it in clean engine oil – the usual type you use and squeeze it in a clean and absorbent cloth to get rid of the excess oil.
  • Place it back to the air filter assembly.
  • Reattach the cover and snap or bolt it in place.

4. Service the Spark Arrester

Many generator owners don’t maintain their unit’s spark arrest, the piece responsible for preventing sparks from leaving the exhaust and causing a fire. Failure to clean it results in degraded performance. So, you want to keep it in good condition to prevent even the possibility of blocking the exhaust passage.

How to Clean and Service the Spark Arrester:

  • With the generator engine completely cooled down, remove the screws holding the muffler to access the plate holding the spark arrester.
  • Remove the screws holding the plate, and the spark arrester will come out with it.
  • Detach the arrester screen and carefully brush off the carbon deposits on it with a soft wire brush.
  • Replace it if it has any signs of wear and tear.
  • Position it in the muffler and screw in the bolts that held it in place.

5. Clean the Generator Regularly

It might surprise some, but cleaning a generator before storage can help a lot, especially during the next usage. Storing it with all the dirt and oil spills can make a mess as time goes by. It’ll also be tough to check for leaks.

It also prevents the accumulation of dirt or grime throughout the machine, which again causes rusting and other types of damage that may be hard to avoid otherwise. Plus, clean units tend to run smoother, too, which contributes to longer unit life.

How to Clean a Generator:

  • You can use a damp cloth to wipe the engine’s exterior surfaces. However, you will need a soft bristle brush to clean the stubborn dirt and oil.
  • Use an air compressor with less than 25 PSI to remove the dirt and debris around the engine crankcase.
  • Don’t forget to inspect all the air vents and the cooling slots (if yours has them) and make sure they are clean and unobstructed.

Pro tip: Avoid using a garden hose to clean your generator as water can enter the cooling slots and damage your generator windings.

6. Generator Battery Maintenance

Does your portable generator have an electric start? If it does, it’s equipped with a battery that provides the needed voltage to start the generator. Most of these units also come with an automatic battery charging circuit that sends the charging voltage when the generator runs.

Generator Battery

The battery can maintain the necessary charge when you use the generator regularly, let’s say one in two weeks. If you use it less frequently, you must connect the battery to a trickle charger or use a battery maintainer to help keep it charged and maintained properly.

If the charge is extremely low, the charging circuit in the generator might not be enough to recharge the battery. So, you will have to connect it to a standard automotive battery charger before using it.

Follow the battery maintenance and storage instructions included in the generator manual and use the battery charger as given instructions.

NOTE: Float chargers maintain battery condition over extended storage periods.

7. Make the Necessary Adjustments

The air-fuel mixture has to stay in the right ratio for the generator to perform optimally. For one reason or another, the adjustment screws in the carburetor might lose their position and require readjustments. The governor might also lose its position and affect the generator’s overall performance.

Unfortunately, tampering with these adjustments might damage your generator, the electrical devices connected to it, or void your warranty.

So, unless you’re sure of what you’re doing, I recommend contacting your generator manufacturer’s service line for these adjustments.

8. Run the Generator Regularly When in Storage

Always remember to run the portable generator regularly. It helps keep everything in working order and ensures that it is ready for immediate use when you need it most.

If you fail to do this, the unit can get damaged or corroded due to lack of usage. So make sure you give it an occasional workout if possible.

This is especially important if you’ve stored the portable generator for long periods. It would be best if you started up your portable generator at least once every month to keep it in good condition all year round.

Run it at least once in two weeks and for at least 30 minutes to give the oil time to reach all the parts of the engine that need lubrication.

Portable Generator Maintenance Schedule

It would be best if you prepared a practical and effective portable generator maintenance schedule. Normally, you can find this information in your generator’s manual. But not always. After detailed research, I came up with this service interval schedule that works for many portable generators.

Pro tip: if you’re not up to the maintenance task, contact your generator’s helpline or visit the nearest certified service dealer near you.

Service Interval/PeriodType of Service
First 50 Hours of RuntimeChange the engine oil
After Every 8 Hours of Runtime or DailyCheck the engine oil level
Clean the muffler and air filter
Check for leaks around the hoses
After every 50 hours of runtime or a seasonClean or replace the air filter
Change your generator’s air filter if it’s been operating under heavy load or in a hot environment
After Every 100 hours or a seasonClean or adjust the spark plug
Change the engine oil
Clean the fuel tank and the air filter
Clean the spark arrestor
After every 250 hoursClean the engine combustion chamber
After three years of operationReplace the generator fuel line


  • When testing the generator, run it outdoors. The generator exhaust contains carbon monoxide, an odorless and colorless killer gas.
  • Avoid accidental ignition of the generator during storage by ensuring the ignition switch, the battery switch (if yours has one), and the ignition switch are on the off positions.
  • If you’re storing the generator for longer periods, consider disconnecting the battery and storing it properly.
  • Never operate your generator if damaged or defective. Fix it and then use it.
  • Tampering your generator’s factory set governor can void your warranty.
  • Incorrect portable generator maintenance can also void your warranty.

About the author

Sharif Gen

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