Engine runs poor on 89 e free octane from inland gas pump. Runs great at local gas pump ethanol e 10 87 octane. I think the e free gas is old. There is no market where the e free is sold. I can't rule out anything else with the engine. Checked carbs, timing etc. It has about 10 hrs on it. Saturday it ran like shit on a full tank of e free and ran great today on fresh e10.