I purchased a used 14 ft fisher single council...with a 15 hp mercury 4 stroke the previous owner said the the boat would not break plane...i tested it...the prop was a 9x12 i went to a 9x10.5 results were the same except i put on an electronic tach. what i found was the top cylinder was sparking twice as much as bottom. full out top was at 4200 and bottom at 2100... is this possable and what could be the cause?.
