Re: 1989 200 evinrude fuel issues
You don't say when those carburetors were rebuilt. When was it?
Engines, when not in use, are normally in a tilted position and tilted (swung) to one side. Boat owners will always have the engine swung to the same side when tilted due to the location of the control cables, wiring harness, steering setup etc.
The tilted, swung position allows three of the high speed jets on one side of the carburetors to be much lower than the three jets on the other side..... and while sitting, three of those jets will foul and gum up faster and worse than the other side.
Your explanation of the problem (no fuel to one bank) indicates that this would be your problem. Note that when cleaning those float chamber bowls, carburetor solvent really doesn't do a proper job of cleaning those jets. I've found it best to carefully clean them manually with a piece of single strand steel wire... they may be cleaned in place but remove them (all 6) from the float chamber bowls if possible.