I am not exactly sure what RC showcase recommends to break in this engine but they recommend 40:1 with a good quality petroleum based 2 stroke oil on their ZDZ engines. After that they recommend 50:1 petroleum based, then 50:1 synthetic. I would not run the engine of the ground for extended periods of time. Run it long enough to set the idle and get a good transition then go fly the plane. Keep it on the rich side for the first few flight. Listen to the engine, if something doesn't sound right get the plane down and correct it.