Bought a used 2015 Bennington 22 S Series. Has a 115 Yamaha (60 hours) with center toon that is not full length. (still learning proper terminology). Wondering what expectations should be on speed? Have been able to pull slalom and wakeboard, took quite a few tries with slalom and top speed is only about 21 and RPM from 42-58 only gains about 1-2 MPH? Is all this expected?