Last weekend, a few of us took our seville mid cabin out fishing. 5 adults. The boat would take forever to plain. With her at full throttle, she would run around 3k rpm at about 10mph. Absolutely would not plain even with the trim tabs down. When I had a one person move towards the cabin, she would finally plain and rpm and speed pick up to around 3500 rpm at about 27-30mph. When I’d let off the throttle to around 3000-3200 rpm she would continue to cruise at around 20mph. If I’d lower the rpm anymore, 2800-3000rpm she will slow down and drag to 10-15 mph. The motor is mercruiser 5.0. Am I just heavy? Or does it sound I’m over propped?? Is cruising rpm noted above too much? I don’t want to hurt anything.