I bought a 2003 16DLX Carolina Skiff with a Yamaha 50 hp F50TLRB engine and it never ran quite right by popping on fast acceleration and a noticeable miss on normal acceleration. It has sat most of its life so I assumed it was a gummed up carb. It always noticed it had a miss and would pop and stall on acceleration. Carb rebuild time right? Yes, well after a full cleaning of all four carbs, #4 carb now FLOODS the cylinder and shuts it down after just one minute of running due to being too rich. Before it floods it runs strong and smooth. I had suspected the enrichers but I checked them by 1. disconnecting, 2. switching location. No help. I then swapped the float bowl and needle from carb #3 to see if the bowl was flooding. No help. My question is, what about the flat rubber gasket on the top of the carb. Could it go bad enough to cause a rich mixture. I will today try swapping the gasket with another carb and see what happens.

Any ideas? PS, the electrical system works great and has great spark on cyl 4 with new plugs. As soon as I clean the pulg when fouled, it will pick up the cylinder again but then flood it out after a minute. Please help.