Simonini Mini 4The Simonini Mini 4 is an Italian aircraft engine, designed and produced by Simonini Racing of San Dalmazio di Serramazzoni for use in ultralight aircraft.WWW Official SiteDesign and developmentThe Mini 4 is a single cylinder two-stroke, air-cooled, petrol engine design, with a poly V belt reduction drive with reduction ratios of 2.56:1 and 2.78:1. It employs capacitor discharge ignition electronic ignition and produces at 7200 rpm.