have hornet trainer plane it flies great compared to nexstar plane. had to take engine and elects. from nexstar to operate it. vmar engine locked up while on stand have had it replaced need to find correct fuel to break in. the engine starts and runs as good as os 46 but need to know more on breakin read report in one magazine on test but the factory tells me to use 5% nitro 20% castrol who makes this and what is name brand donot want to ruin 2nd engine. was running on 15% nitro from os46.