Oxygenated Fuels Gone Bad

 March 22, 2010

This is the sixth post of Exmark’s ten part Service and Maintenance Series.

Milk. Parking meters. Unused gym memberships. Some things are meant to expire after a certain period of time. Fuel for your mower is included in that list.

Oxygenated fuels (fuels containing alcohol blends or MTBE—methyl tertiary butyl ether) have a shelf life of 30 days. This should prompt mower owners to mark the date on their gas cans when filling up. It is an easy step to ignore or forget when starting fresh with a new season. Using old fuel can contribute to poor engine performance and a decrease in horsepower, along with a string of other problems. Plain and simple, mark your cans and dispose of old fuel.

In addition, fuel should be checked to ensure that it does not contain over the maximum 10 percent alcohol or 15 percent MTBE. There are plenty of inexpensive testers out there, so make sure you pick one up.

Our next post will be about blades, so check back soon.