Elevate the generator on bricks or blocks of wood to create clearance for the catch pan. Make certain that the generator is level.
Locate the engine oil filler spout below the fuel shut-off valve and next to the grounding lug. Remove the oil filler cap from the filler spout.
Locate the engine oil drain plug at the bottom of the muffler side of the unit and below the inboard edge of the air cleaner. Position the catch pan under the drain plug. Remove the drain plug, using a crescent wrench. Allow the engine oil to drain fully from the engine.
Replace the engine oil drain plug and tighten it securely. Set the generator down on firm, level ground.
Add 20 ounces of engine oil through the oil filler spout. Screw the cap securely on the spout.