Engine hesitates at around 65-70 mph, once you let off, it will pick back only to fall on its face again. Changed Fuel/water separator filter, clear bowl filter, VST screen, high pressure filter and spark plugs. All of the basket filters were replaced last year as routine maintenance, nothing looked bad, so I didn't mess with them. My delima now is do I tak it to a shop and if so will they be able to troubleshoot it? Boat runs great at anything under 65 mph. Any suggestions ?