1. Park the mower on a flat surface and allow the engine to cool down.
2. Disconnect the spark plug wire to prevent the engine from starting accidentally.
3. Remove the oil drain plug. Allow all of the oil to drain into a suitable container.
4. Replace the oil drain plug.
5. Remove the oil filter.
6. Apply a thin coat of new oil to the gasket of the new oil filter and screw the filter into place by hand. Tighten the oil filter with an oil filter wrench until it is snug.
7. Add the recommended amount of new oil to the crankcase. The recommended oil type and amount can be found in your Murray mower operator's manual.
8. Check the oil level with the dipstick and add more oil if necessary.
9. Reconnect the spark plug wire.
10. Start the mower and let it run for a few minutes.
11. Check the oil level again and add more oil if necessary.
By following these steps, you can safely change the oil in your Murray 3.5 HP mower.
