Quick question: I have a 2015 nitro with a mercury 150 opti max pro xs around 225 hours. I left the ramp in the morning motor was doing fine got to my first spot and fished for 3 hours or so. Then I was trying to leave and when I was starting the engine its was revving up and shutting down. It did it 5 times, finally it started ok headed back to the ramp. It did it again when I was going to put it on the trailer. So I just pushed it on. When I got home I started it to check it and it's running normal. Anyone ever had that problem?

Check for loose cannon plugs and ground wires. I always do the simple stuff first just to eliminate those items and narrow down the search.

Your getting fuel in the air side of rails either a leaking fuel injector or a bad diaphragm in your tracker valve or fuel pressure regulator........OPTI

Had sameproblem was fuel D�aphram. Had replaced problem solved

Looks like you got good advice here but if your problem persists check out this site https://forums.iboats.com/forum/engine-repair-and-maintenance/mercury-mariner-outboards, make sure to give your motor s/n right away and you will get good advice. If you are a total rookie they might suggest you see an expert, don't take it the wrong way.