I just bought a new G3 1036 jon boat and max hp is rated at 5hp . Can i go any higher like a mercury or yamaha 8 hp or 9.9 . I went to bass pro shop today and the mercury 5 hp weight is 56 lbs and the 8 hp is 84 lbs not a big difference. my weight is 280-290lba and want the biggest i can safely use