During routine maintenance, mistakes can happen. When the mower is turned on its side, oil can leak into the gas or simply spill when re-filling the reservoir during an oil change. In most cases, these mix-ups occur when the labels of oil and gas canisters are incorrectly labeled. Operating the mower with oil clogging the fuel filter will lead to mechanical problems that require a service call. Cleaning the oil, filter and gas quickly will prevent permanent damage to the mower and get you back to cutting the lawn in no time.
Remove the sparkplug wire from the plug. Unscrew the sparkplug and discard. Push the mower to a well-ventilated area, outside.
Remove the oil from the mower, following the manufacturers directions. Many mowers are equipped with a drain plug, located under the mower deck. Remove the plug and allow the oil to drain into an oil collection pan. Empty the gas tank, pouring the fuel into an approved gas collection container. Turn the mower on its side, allowing the fuel to drain out. Dispose of both the oil and gas according to local and state ordinances.
Remove the fuel filter, following the manufacturers directions. Replace with a new filter.
Refill the gas tank with clean fuel and fill the oil reservoir with clean oil. Screw a new sparkplug into place and attach the sparkplug wire.