The motor itself?is not?sealed well enough, and in this saildrive orgintion water can collect on the top of the motor and seep in .
The 4 screws that hold the encoder down can also short out the board, it helps to put fiber washers under these . Sometimes just removing the screws fixes the encoder problem.
Brian D. HAll
ThunderStruck Motors, LLC 2985 Dutton Ave. Ste 3 Santa Rosa, CA 95407 Tel: (707) 578-7973 Fax: (707) 581-1860