<div class="section abstract"><div class="htmlview paragraph">Recently the response of the engine speed at starting has more importance than ever for quick start satisfying rider’s needs, as well as exhaust emissions. We have developed a simulation for studying engine and starter specifications, engine control algorithm and other engine control parameters. This system can be utilized to realize appropriate starting time by considering air-fuel ratio under various conditions.</div><div class="htmlview paragraph">This paper addresses what are taken account of in our method. Examples applying this to a conventional motorcycle engine are shown.</div></div>