Guys, I have a 1992 Evinrude 60 HP 60TENE. What would it take to bump it up to 70 HP. It has enough power for the fishing side, just want to be able to pull a tube, kneeboard and small skier (Grandsons). I love the boat(1992 16FT. Nitro) but it is only rated for 60HP max. I am sure it can handle...