has anyone tried putting a larger 4 stroke than 52 size in a pt-17? mine has an os52 and it seems to be very underpowered especially given its weight. my latest prop is a 12x5. i have a sanyo fs 82-18.5 oz with muffler 1.5 hp 60 size case. weight is no problem since i had to put 3 oz on the front. suggestions? thanks