May I add something on stopping an engine? (Assuming it's installed in an aircraft)make sure you can always stop it by closing the throttle on the tranny. I once had a Super Tigre .90 that refused to start on a first flight after a long winter. It even took so long that I -stupid- tried to make it start with receiver and tranny switched off, matter of saving batterypower. Suddenly it sprang into life with far too high RPM and the plane jumped the chocks, forward a few inches... the prop digging deep in my fingers. There I was, one hand bleeding like the niagara falls, holding the plane with my other hand, my Super Tigre screeming like mad,...and no way to stop the engine.