That motor is what we run in our restricted classes for Hydro, Mono, & rigger with the 45A ESC on 4s. The M645 seems to be the best performer on all three boats. I've tried Prather, ABC, CNC props, TFL props of varying sizes & pitches, But it always seems to come back to the M645. Although a CNC 448 is almost as good on my rigger. I've even seen a 447/3 on a rigger with great success at our club.
Just my observations.
Paul.
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