Was pulling my daughter and her friends this weekend. 2 tubes, 3 on each tube. Part way through the day the boat developed a vibration at certain RPM's and has lost about 13 mph from WOT. Thought I spun the prop hub but I changed props and have the exact same problem. Motor starts great, idles perfect and revs nice when not in gear. But under power it has a very noticeable vibration and will only go 37 mph on the gps with just me and a 1/4 tank of gas. This boat will easily run 50mph in that scenario. Had new injectors installed 3 years ago. Boat is a 17.5' Lund Fisherman. Please help. Thanks
