I have 2 Mercury 250 EFI’s. One of the motors is a weaker motor. The starboard motor has a rougher idle. When acceleration begins the starboard motor stalls at about 3000 rpms when the port motor continues to push to 4000 rpm the starboard motor will “catch up.” Once the boat is on plane it performs okay. I have replaced all filters, spark plugs (Champion QL77C) and wires, swapped the CDM from other motor, tried a different VST tank, put Chris Carson Reeds on it, checked compression all over 105 psi, replaced temp sending unit, tested thermostat, checked out TPS, replaced they flywheel, replaced fuel pressure regulator, replaced the crank and lower bearings and piston and rings, brucato professionally cleaned injectors, swapped ecu and ecm, replaced the map sensor, replaced all bleed hoses, rebuilt fuel low pressure pump, cleaned out midsection for carbon build up, and completely redid the fuel system. I have reset the trigger and have done a dva test on the trigger and tested the stator. I have checked all grounds and have a new battery. I need help!?!? 
