Generac & Portable Generator Maintenance Schedule

Generac GNC-6485 20kW-22kW Generator Maintenance Kit for 2013 & Later Hsb Models

A basic generator maintenance schedule comes down to three habits: check the oil before every use, do an early break-in oil change, and then change the oil on a fixed hour or calendar interval. Generac tells portable owners to change the oil after the first 20 to 30 hours and every 100 hours after that, while its air-cooled home standby generators get a break-in change at 25 hours and then a change every 200 hours or at least every two years.

Below you will find the intervals manufacturers publish, how portable and standby generators differ, how to store a generator, whether you can run one in the rain, and what decides how long a generator lasts. Maintenance kits, covers and cold-weather kits are in our generator accessories section.

Generator maintenance schedule at a glance

Always follow the owner’s manual for your exact model first. These intervals are what Generac and Honda publish for their generators. Each one applies to whichever comes first, the hours or the calendar.

Task	Generac portable	Honda portable	Generac air-cooled home standby
Check oil level	Before each use	Before each use	During long outages, at each 24-hour shutdown
First (break-in) oil change	20 to 30 hours, depending on model	First month or first 10 hours	25 hours of total run time
Routine oil change	Every 100 hours or annually	Every 6 months or 100 hours	Every 200 hours, and at least every 2 years
Hot or cold climate	Monthly under heavy load or high heat	See manual	Every 100 hours below 40°F or above 85°F
Air filter	Clean or replace every 200 hours or annually	Clean every 3 months or 50 hours, replace yearly or at 300 hours	Per manual (included in maintenance kits)
Spark plug	Replace annually	Check every 6 months or 100 hours, replace yearly or at 300 hours	Per manual (included in maintenance kits)
Long outage	Shut down and check oil every 8 hours	See manual	Shut down for at least 30 minutes every 24 hours

Portable generator maintenance

Oil and fuel are the two things to stay on top of with a portable. Generac’s portable guidance adds a few points beyond the table:

Break-in service matters. The first service at 20 to 30 hours includes an oil change and a valve clearance adjustment. Larger models may also need an oil filter change.
Every 100 hours or once a year, change the oil and clean the spark arrestor. Check valve clearance every 300 hours or annually.
During an outage, a portable can run continuously, but shut it down and check the oil every 8 hours or each time it runs out of fuel.

Tracking hours is easier when the generator counts them for you. The DeWalt DXGNR6500 and Generac GP8000E have hour meters for maintenance intervals. The Winco W6010KE meter shows oil-change alerts, and Honda’s My Generator app sends service reminders on models such as the Honda EU2200i and Honda EM6500S.

Generac oil change and standby generator maintenance

A home standby generator exercises itself on a schedule, so it builds up engine hours even in a year without outages. Generac’s guidance for air-cooled models:

Break-in at 25 hours. Change the oil and filter at the first 25 hours of total run time, however those hours were reached, through exercise or outages.
Then every 200 hours, and at least every two years even if the hours are low. Generators that run in very hot or cold weather (below 40°F or above 85°F) need the oil and filter changed every 100 hours.
Oil type. Generac recommends its 5W-20 full synthetic oil. There is one exception in our range: the Generac 7103 breather heater kit for 9 to 22 kW air-cooled units requires 5W-30 synthetic once it is installed.
Yearly checks include inspecting for water intrusion and corrosion, inspecting the battery and doing a fuel system leak test. Generac says standby batteries last about 3 to 5 years on average.
Extended outages. After every 24 hours of continuous running, shut an air-cooled standby unit down for at least 30 minutes and check and top off the oil.

Generac’s FAQ recommends dealer service every 6 months, though owners can follow the manual themselves. Browse our standby generators or read our home standby generator buying guide if you are still choosing one.

Maintenance kits and accessories in our range

A kit puts the filters and plugs for one service in a single box. Match the kit to your engine size and model year:

Generac GNC-6485: 20 to 22 kW air-cooled Guardian (999cc) units from 2013 and later. Includes an air filter, oil filter and two spark plugs.
Generac GNC-5664: 12 to 18 kW air-cooled Guardian units built before 2013.
Generac GNC-5984: 36 kW Guardian units with the turbocharged 2.4-liter engine (four spark plugs).
Generac 7991: liquid-cooled 4.5L engines in the 48 kW Protector QS and 60/80 kW Protector.
Generac 5720: Generac’s 530cc portable engine (check the listing for the exact models).
Cold climates: the 7103 breather heater kit (recommended where temperatures fall below 20°F) and the 7088 extreme cold weather kit for the 48 kW 5.4L engine, which Generac recommends a dealer install.
Propane-fueled standby owners can watch tank level from a phone with the Generac G0070090 LTE fuel level monitor. It requires a yearly subscription.

How to store a generator

Honda warns that gasoline can go stale quickly and cause starting or running problems. Its fuel guidance gives a simple rule of thumb by storage time:

1 to 2 months: fill the tank with fresh fuel with stabilizer added. Honda notes stabilizer will not restore fuel that is already stale.
2 to 12 months, or if you run it less than once a month: drain the carburetor, whose small amount of fuel goes bad faster than the tank’s. The DuroMax XP13000HX fuel selector has a setting that runs the carburetor dry before storage.
More than a year: drain both the fuel tank and the carburetor as the owner’s manual describes.

Generac’s kit notes add that if a portable has been stored for several months or run for long periods, change the oil and fill it with fresh gasoline. Store fuel outside living areas in labeled, non-glass safety containers, never near a fuel-burning appliance such as a gas water heater (CPSC guidance). Keep dust and UV off a stored unit with a cover such as the Generac 6811, which fits most 5,000 to 8,000 watt portables. Remove any cover before starting the engine.

Can a generator run in the rain?

Not out in the open. The CPSC warns that generators pose a shock and electrocution risk, especially in wet conditions. If you must run one while it is wet outside, put it under an open, canopy-like structure on a dry surface where water cannot reach it, puddle or drain under it. Never move it into a garage or shed to keep it dry: the CPSC warns carbon monoxide can reach deadly levels within minutes, even with doors open.

For a semi-permanent setup, a purpose-built enclosure is another option. The ZombieBox XLarge package is built for weather and theft protection and noise reduction. It requires at least 5 inches of free space on all sides of the generator, so check your generator’s dimensions first. See our quietest generators guide for more on noise.

How long do generators last?

Manufacturers don’t publish a single lifespan figure that fits every generator. Generac says its home standby generators are built to last decades, and it ties performance and lifespan to following the maintenance schedule. For any generator, portable or standby, these factors are in your hands:

Oil discipline: on-time changes, especially the break-in change.
Fuel: fresh or stabilized gasoline and a drained carburetor during storage, as Honda recommends.
Load and hours: how hard and how long it runs between services. Heavy loads in high heat shorten Generac’s portable oil interval to monthly.
Environment: dust, heat, corrosion and water. Generac’s yearly standby checklist includes inspecting for water intrusion and corrosion.

For how many hours a generator can run on one tank or fuel supply, see how long can a generator run.

Service parts matched to Generac engines are listed under Generac maintenance kits.

Frequently asked questions

How often should I change the oil in a generator?

For Generac portables, after the first 20 to 30 hours and then every 100 hours or yearly. For Honda portables, after the first month or 10 hours and then every 6 months or 100 hours. For Generac air-cooled standby units, at 25 hours and then every 200 hours, and at least every two years. Your manual takes priority.

Does a generator need maintenance if I rarely use it?

Yes. Generac sets a two-year minimum oil change for standby units regardless of hours. Fuel in a portable goes stale whether or not the engine runs, so stabilize it or drain the carburetor.

How do I store a generator for winter?

Change the oil, then stabilize fresh fuel for a 1 to 2 month layup, or drain the carburetor (and the tank, beyond a year). Store it clean and covered, with fuel kept outside living areas.

Generator Maintenance Schedule: Oil Changes, Storage and Lifespan