Fuel requirements for 4-Cycle and 2-Cycle engines are different. Please see the instructions below and refer to your Operator's Manual.
4-Cycle Engines: John Deere recommends the use of regular unleaded gasoline intended for automotive use with an octane rating of 87 for all 4-cycle engines. The use of higher octane fuels such as 89 or 92 octane can lead to deposits on the valves, which will cause poor running conditions and reduced performance of the engine. These engines are commonly used in lawn and garden tractors, pumps and generators.
2-Cycle Engines: For 2-cycle engines (most commonly used on string trimmers, chain saws and blowers) you must mix the unleaded fuel with a high-quality 2-cycle engine oil.
The preferred oil for John Deere 2 cycle equipment is John Deere Premium 2 Cycle Oil, also known as Exact Mix. When using John Deere Exact Mix, it should be mixed with fresh, 87 octane fuel in a 50:1 ratio. This would be 2.6 ounces of Exact Mix with one gallon of fuel. When this oil is properly mixed it can be run in any 2-cycle unit, regardless of the mix ratio. Note: CS71 and CS81 chainsaws require a minimum of 90 octane fuel mixed with oil in a 50:1 ratio. Additionally, Exact Mix oil contains an antioxidant fuel stabilizer.
If John Deere Premium 2 cycle oil is not available, any brand of premium 2 cycle oil can be used that is classified as grade ISO-L-EGD or JASO-FC. Note: Do NOT use 2 cycle oil intended for marine or boating applications. When using other brands of 2 cycle oil, it should be mixed with fresh, 87 octane fuel in a 32:1 ratio. This would be 4 ounces of 2 cycle oil with one gallon of fuel.