2004 Glastron gx 205 w/volvo penta 5.0 with a 14-1/2 x 19 aluminum prop. I use this boat for wakeboarding and pulling tubes so speed is not what i'm looking for. I have owned this boat for about 2 months and notice that on wakeboarding and tubing it loses speed and rpm in turns. It struggles while pulling some wakeboarders up. any help would be appreciated.