You know, that's almost sounding like water in the gas. btw, an easy way to check your fuel flow into the carbs (and check for water in the bowls) is to open the bowl drain screws (one at a time and is item # 16 in the pic below. Put a little cup under the carb to catch the fuel. This is a fast way to eliminate the tank and lines to the carbs and may or may not show you water.
Definitely check the stuff jj mentioned.
