What is over reving? I have heard people say to be careful when getting a new prop, that you don't over rev. But I have talked to others that say barefooters run there boats at 5K rpms all day long. What are your rpms at ~23mph?
Over revving is running the engine at above its rated speed. New engines have rev limiters that prevent it in most situations. If a prop is too easy to spin it might let the engine run too many rpm and over stress the parts. Running an engine at high revs for a long time is stressful but if the engine is designed for it it only means higher wear but not damage.
Over reving is rpm based , has nothing to do with speed,if an engine is designed to run between 4800 and 5200 RPM 5300 is over reving mainly causing internal failure , spinning bearings and throwing connecting rods!!!!!!!!