Jerry pretty much said what the rest of us have been saying. He is correct about the fuel coming out around the throttle shafts if enough goes into the throttle body with the butterflies closed. Also while you are checking all the rest you might want to put what they call whistles in the carbs. They will keep gas from splashing up under braking and going into the vent areas. I had to have that done with mine and what a difference it made. If your pressure has been to great you could have the needle valves all messed up. My book on the 900 Holly I am running calls for just 6 to 8 pounds of pressure. My pump puts out 14+ so I have to watch it and make sure the regulator doesn't back off or the filter get full of crap. The gas out the muffler is just unburned raw fuel which has poured into some cylinders and is being ejected. Not good as some of it most likely went into the
oil pan too. I would have both of the carbs checked out completely along with the rest of the stuff Jerry mentioned, and then change the
oil and filter to make sure there is no gas in the
oil.
Ron