Trying to figure out if I got enough?

”” Yes I was brushing up on my propeller design and the manufacture states that
The propeller was designed for max of 2900 rpm
So the propeller 2900 X 1.9= 5320 rpm on the engine
That seems like max rpm for a engine but have no idea ? the propeller is pitch adjustable

“” Adjust the blade pitch angle to fully load your engine at full throttle up to the engine redline rpm, or 50 to 100 rpm below the engine rpm redline. The propeller becomes, or replaces, the engine's rpm "governor". If for an aircraft, set the maximum full throttle rpm for flying straight and level at your typical cruising altitude upto the engine redline. If for a boat, set prop pitch to limit engine rpm to or just under engine redline rpm when on plane (or as fast as the boat can go) in smooth, calm waters .

Obviously you will need a tachometer connected to your engine. This procedure applies to ALL engines at or just under engine redline rpm turning a propeller to produce maximum possible THRUST per HP””

Updated research data
“”The Kawasaki FD620D engine is capable of producing a maximum 20 horsepower at 3,600 rpm. It can also generate a maximum 32.9 ft.-lb. of torque at 2,200 rpm.””