My 85hp is a dog with three people in it total of about 520lbs it planes sluggish put one on a tube and i have to jump a wake to get it to plane at all....It is on a 87 bayliner capri 15 foot I currently have a 12 5/8 21" pitch prop which i know is too much I need some suggestions on what kinda tach i need and where to get one to give more details......... With 2 people without a gps i think it will pull around 45mph but with 5 people i am looking at 10mph...Im thinking of a 13" 17p prop since i will be carrying 4 [people most times[one on the tube] and the guys on the force forum told me it was way overpropped:redface: