2000 Rinker Captiva bogs at 2000 rpm and won't go above 25 mph

Was taking the boat out on the water and for the first time ever couldn't get the engine to rev above 2000 rpm, it wouldn't go above 25 mph, and wouldn't plane down all the way...never had this happen and have heard stories from the prop to fuel pumps to oil sensors...any advice would be great!!!