Kind of Oil

• The crankcase needs constant lubrication to keep the engine from seizing. In hot, summer temperatures, the engine will produce a lot of heat, and the proper engine oil will be needed to keep those temperatures from rising to a critical point. Yard Machines suggest using a SAE 10W-30 that meets all federal oil requirements. This grade of oil will protect the machine in most weather types. However, if the temperature should drop below 40 degrees Fahrenheit, you may want to use a 5W-30, though this isn't a requirement.
  
  

Checking the Oil

• The oil needs to be checked frequently, ideally before each use, in order to prevent the oil level from slipping too low and damaging the crankcase. Unscrew the oil dipstick and pull it from the oil tank. Wipe the end of the dipstick and screw it fully back into place. Pull the dipstick out again and check the oil reading. If the oil level is into the "Add" section, you will need to add enough oil to reach the "Full" section before using the lawn mower.
  
  

Filling the Oil

• If the oil reading is low or the oil was just changed, you will need to fill the oil tank with a fresh supply of engine oil. Open the oil filler cap and set it aside. Use a funnel or a spout to help guide the oil into the tank and prevent oil spills on the engine, which could start a fire. Slowly add oil, about 1/4 cup at a time, allowing the oil to settle into the tank before adding more. While adding oil, periodically check the oil level on the dipstick. Don't over fill the oil tank, which may harm the engine.
  
  

Changing the Oil

• The oil on your Yard Machine lawn mower needs frequent changing, just like your car. The recommend period is between 30 to 40 hours of operational use. Oil change methods vary widely from Yard Machine models and from walk-behind to riding mowers. Some methods will require removing a drain plug, while other mowers can just be tilted onto its side, allowing the oil to drain out the oil fill hole. Check with your manual's oil changing specifications, and if you feel unqualified, allow a service mechanic to change the oil.