I have a 1998 290 sundancer with twin mercruiser 4.3 ltr 190 hp engines. Starboard engine is running fine, but the port engine developed a ticking sound that started this week during a test run of new props. I put the new props on and went on a test run and noticed that the rpms ran a bit higher than before, but it ran well at 22 knots at 4,000 rpm's. The port engine rpms dropped to 3,000 at near full throttle and I stopped and heard the ticking sound at idle 700 rpm and then I heard less of a ticking sound at a around 1,500 rpms. Sorry, videos to big to attach. I googled this and got answers all over the place from exhaust gasket, fuel pump, water pump, valve lifters, or new engine. Feedback appreciated. Thanks If you want to view the videos send me your email address.