I have twin 1995 150 hp Johnson's on a Wellcraft 238CC. When I got the boat 5 years ago it would run 50MPH GPS at 5800 WOT using OMC 14.5 x 19 Prop P/N 389924 screws.
I now have over 1100 hours on it and the speed is dropping even though the RPMS are staying at about 5800 WOT. The props have...