99 merc 200 carb rough idle cyl 1 and 2 missfire

[red82z28]

So i have a 1999 Mercury 200 xl Carb Serial number og805600! Iv been trying to diagnose a rough idle problem for 2 weeks now! So far i know that cylinders 1-2 are not firing but are getting spark and fuel! Engine has no problem starting and doesnt stall at all! Just runs rough and idle seems to be high! I can pull the spark plug wires off both cylinders with no change in how it runs what so ever and also i can screw in the mixture screws on the carb all the way with no stalling. So far Iv changed trigger, stator, both rectifiers, reed valves, cleaned and rebuilt all the carbs, fresh plugs, and timed everything. Compression in all cylinders is 120 and fuel pressure is at 5 psi. Iv done dva tests according to the mercury service and everything checks out. I cant figure this out for the life of me. Talked to 2 marine mechanics which both tell me this things should be running like new. Can anyone help me out here please?