I am thinking this is a common problem because my neighbors boat and my boat both do it. We both have 3.0l mercruiser engines. His is a 1987 and mine is a 1992. His uses points for ignition and mine has the electronic ignition that you have to wire in the jumpers to set the timing correctly. I ran my boat at about 4000 rpm for about 15-20 minutes non stop. When I eased back to about 1/4 throttle, it starting surging real bad like it was running out of gas. The surging happened within 2 seconds of lifting the throttle. This is the first time that this has happened to me. My neighbors boat does it all the time under the same conditions. His doesnt have to run as long as mine at a constant speed to do it. Anyway, I eased up into idle and then back to the same place on the throttle and it quit doing it. I watched the temp gauge and it all looked fine. Both of our boats never go over 170 degrees. What could be causing this. If the carb wasnt getting enough fuel, I would think that it would have a hard time running perfectly at 4000 RPM without a miss. Anyone else have/having this problem and has anyone ever fixed it. Thanks in advance.
