For best engine life, the oil should be changed every 75 to 100 hours, or annually, which ever occurs first.
The unit comes with a dipstick type oil pump for changing the oil. Start and run the engine for several minutes to get the oil warm. Stop the engine and remove the Dipstick. Insert the oil Dipstick Pump tube as deep into the engine as possible. Suck the oil out using the pump, and dispose of it according to EPA regulations.
Remove the oil Fill Cap and add one quart of approved oil. Replace the oil Fill Cap and Dipstick. Start the engine and let it run for one to two minutes. Stop the engine and check the level on the oil Dipstick. Adjust the level as necessary.
With practice, the amount of old oil removed will be just the right amount, so that adding one quart of new oil will bring the level up to the correct level.
Although there is an oil Drain Plug on the engine (3/15), it is too low on the generator to provide easy access for draining.
Installation of an adapter at this location for drain pumps, etc. will automatically void the warranty.
The Air Cleaner housing contains a dry element filter. Remove it and shake the accumulated dirt from it each time you change the oil. The element should be replaced every 250 to 300 hours.