I took my boat out this weekend and the boat started up fine and idles fine. At low speeds it was fine then when I wet to take off I hit somewhere around 20 mph and it died and started running rough. Then came to idle and it was fine. So the boat runs fine but won't get to above 15 mph without loosing power. I had the local nautique dealer do a tune up on it (sparks plugs, rotor, and cap) but the problem is still there. So before I drop a huge bill on them starting to find the problem I wondered if anyone has had this problem or had any ideas.