Im having a problem finding the right prop for my 17'Boston Whaler Montauk 98 with 98 Merc 90 hp. The boat would do 50 mph all most scary in a 17" boat that's about 1300 pounds loaded. But now Im lucky if i get to 30 mph. The prop size is 13-1/4 by 21 i changed the hub twice still no go also got a michigan wheel raptor SS prop same numder prop 13 -1/4 by 21 it ran just as bad . I get the rpm's up to 5200 but no speed. Could i have a deeper problem then a prop?
