1987 Force 85hp went thru all three carbs as gas was coming out the vent in the bottom carb so replaced needle and seat. The other two seemed fine at the time. Hooked it all back together and now gas is coming from the top carb. We blew thru the carb and the needle did not allow air to escape thru the vent hole but gas blows right thru it. Any suggestions? Thanks for the help as I am a rookie