I have tested this engine and people are silly if they sell them i ashore you will be kick your self when you see one run. The engine is wicked very fast as fast as most outher engines. I tested mine today at a club race and the engine is a shinning paformer very fast consistant relable and powerfull. It was faster then most top of the line engine such as ninja ro1 and its not far off a 35+21 in the paformance if you gear the engine right its as quick. I defnatly recamend useing it for any type of racing. Its very impressive to say the lest. Regards Jeremy.