hey guys I need some input, 350 mercruiser 260 horse thunderbolt ignition, my motor kept cutting off on me yesterday would run great take off great when I would get up around 40 45mph my motor would just turn off like it was just losing spark, then it would just start back up and run ok until it did the same thing again. could it have something to do with the ignition control module thats mounted on the riser

Yes could be ig module or bad connection at coil or bad coil all together.

does not look like I have any bad connections, how can I tell if its the coil or the control module, when a control module goes bad on a boat is this how they act, shut down but then starts back up and runs fine until Im on a plane and then just shuts down,

try a new coil. Mine did the same thing, except mine did it at about 3k rpm. Would run fine below, then die above 3k rpm. A coil is so cheap, try it and see if it fixes it .

thanks for the help guys