I just put 2 150 (95) johnsons on my boat. I have 2 question. I have 2 gas lines going into one water separator filter (2 inlet/2outlets. Should I have 2 seperate filter/separators? Second question; can both my starter bateries be tied together (12 volt) as with a single ourboard. Don't want to fry the charging systems. Grounds on both motors are togethetr on wiring harnes as book suggested.<br />Thanks Rick