I flew the 1.40RX's for years. They are great engines. My test now for engines it do a vertical snap and see if the plane will pull out with authority. It wont. It just doesn't have the torque. It's kind of like the YS 1.40's. Great engines, but their time has come and gone for a TRULY COMPETITIVE engine. There are just things that are better. In a VF3, the 1.40RX would be a dog. The 1.60FX is OK, but doesn't touch the performance of a YS 1.70 or a competitive electric setup. Great engine, but not for the size that the planes are getting now. You could fly one in a 10lb Prestige or lighter integral and get away with it in lower classes, but once again, do a vertical snap or multiple vertical rolls and when it gets to the top corners it is really struggling.

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