Expanded Small Engines Ethanol Storage Study

Minnesota State University-Mankato/Gary Mead

This study will determine the effects of E10, E15 and E20 on the fuel systems of small engines found on handheld and non-handheld power equipment. It will investigate both material compatibility and performance issues. This study is an expansion of the small engines storage study conducted at Minnesota State University-Mankato from 2012 to 2014.

During that first storage study, it was discovered that ethanol blended fuels did have some effects on certain types of carburetors. The expanded study will investigate additives to mitigate the negative effects seen on low-cost diaphragm carburetors and will continue the investigation on float type carburetors. Both 2-stroke and 4- stroke engines will be tested. The test is designed to closely mimic how consumers treat their power equipment. Sixty-four engines will be required to ensure a large enough sample. This will be broken down into 32 handheld 2-stroke pieces of equipment, 8 per the 4 fuels, and 32 non-handheld 4-stroke pieces of equipment (8 per fuel).

Each piece of equipment will be assigned to a specific fuel and performance measurements will be made. Then the equipment will be stored for six months with the fuel tanks half full of fuel. After the sixmonth storage period, the equipment will be started and the same performance measurements will be taken again. Next, the equipment will be stored for another six-month period and then performance measurements will be taken again. Finally, the fuel systems will be disassembled to check for material compatibility issues.