Mercury 90CT 2018

by Bob
(Milton, Florida, USA)

I have about 170 hours on a 2018 Mercury 90CT Four Stroke attached to a SunTracker 20' Party Barge. Recently, after running it at approximately 4,000 RPM for about an hour, the engine will start skipping - losing about 100-150 RPM for a second, and then going back to normal RPM. It runs flawlessly for the first hour or so. Changed out spark plugs, added Techron, and have only used non-ethanol fuel since engine was new. Problem still persists. Also, fresh water use only. No Observed Faults on Vessel View. Engine temperature at 4,000 RPM is about 135 degrees.

Fuel pump or ignition coil, breaking down after getting hot are a couple of my thoughts. Any additional insight would be greatly appreciated.

Thanks.


Bob D.