Basic answer: No



But....given that engines rotate counter clockwise, slap on a pinion on fhe output shaft, then a big counter gear, its pretty obvious why most of them are clockwise rotation.

There's a few that use belt drives or the like that rotate the other direction.

Since most electrics are based on their nitro brothers or use the simple pinion/counter arrangement, many of them have a right hand main rotor as well.

For a scale application I took a Logo 10, swapped two motor wires, turned the blades and paddles over, and turned over the autorotation bearing, and it flew just fine (though it was weird for a while seeing it lean right instead of left)