My 2006 Bayliner has a Mercruiser 3.0 in it and it starts right up after I pump it twice with gas after about 3 weeks of not using. When I stop in the lake to let the kids swim and shut it off it has trouble starting back up. It will start after the 3rd or 4th time just wondering if I should pump it with gas a cpl times before starting or what the problem could be? I am a new boater so I don't know much about boats.