Re: max rpm 50 hp mercury??
Tyler, now that you know your WOT RPM range, without a tachometer, knowing if you're exceeding the maximum RPM is impossible. However, if your boat is between 14 and 16 feet in length, the propeller is the factory recommended size and style, and your WOT timing is set to factory specs you'll probably never exceed max RPM by any damaging amount.
If you've altered the timing or changed the prop then you should install a tachometer to monitor max RPMS and also see if the changes you made were effective or not.
Here's the funny part, the original warranty states to never exceed max RPM's. Dealers, boat manufacturers, customers, ect. installed thousands of these motors on boats without any means of knowing (tach) what the max RPM's were. It was Merc's golden parachute for voiding warranties.