mercruiser 165 high rpm miss

[73Marauder]

finally got the boat out on the water for the first time this year.
I am having some issues with the starboard engine
this morning the engine did not want to idle when prepping for the trip during troubleshooting I discovered that the idle circuit was lean and adjusted the mixture screws for maximum vacuum. ended up with more than 20 inches of vacuum and an engine that idled well and operated up to about 1500 rpm with no miss.
This afternoon on the water the engine was obviously not performing as well as its twin missing and carrying on it is at higher rpm above 3000 really takes the wind out of your sails when you are hoping to make some time on the water. I did reset timing while we were out and that appeared to help but Im not sure where to go next.

 

[NHGuy]

Will it rev past 3000 without load?
It's possible that you're not getting timing advance. So does this distributor have mechanical advance? If it does, check that the mechanism is not stuck. Put the light on it and rev it briefly to your problem RPM. If no advance, grab the rotor and twist it against the springs. If it's sticky, free & lube it in a way that won't get lube on the electric stuff.
But if you are getting advance, start checking fuel delivery and finally carburetor.
Fuel delivery, dump the filter in a jar and check for both water and debris. If you find water there's a chance your carburetor bowl has water too. If the filter is clogged perhaps it was that. When was it last changed? Also check the fuel inlet screen at the carb.
If it's none of that try running with the fuel cap loose to rule out a clogged tank vent.

 

[73Marauder]

fuel delivery is good the other engine is plumed from the same fuel tank. I will check the mechanical advance that is one I had not thought of. I am fairly sure after reviewing the symptoms and recent work I am fairly sure I have a carburetor problem.

 

[73Marauder]

and by the way since I forgot thanks for taking the time to respond I find it really helps to get others involved to think of things I don't.