You should be using 105 or corn head grease in the gear case, not gear oil. This link will explained what your issue is and some tips on how to solve it. http://pochefamily.org/outboard/CarbService.html Its a common problem with this carburetor. You’ll likely find witness marks on the side of the float bowl where it has been hit, trying to stop it from running over.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
