RE: Fuel??
Actually a good quality race fuel is not ideal for breakin in the engines.......Race fuels use high grade lubricants that protect so well they do not allow the proper metal to metal wear needed to lap all the moving parts together..... Which in turn drastically extends the breakin process and puts unnecessary wear and tear on the internals, and sometimes ends up with a poor piston/sleeve seal..... I recommend using a cheap fuel like HPI for breakin, then switching to a quality fuel when its time to runt he engine.........