Nice video from DADS50! At the end you removed a spring... I take it you modified so that air inlet valve will hang open?
Mick53: ethanol for sure! I think pump gas around here comes with 5-10% ethanol... something not anticipated by the original designers.
I've heard that aluminum tanks actually corrode if ethanol content is greater than 10%.
www.nmma.org/assets/cabinets/Cabinet103/E20_Position_Paper.doc