We have a 93 Merc Mariner and we just can't get it to fire. It's been cold here, but we tried several times once it warmed up too. It just won't fire. We have new plugs, battery and drained the fuel line. There is plenty of spark and it's definately getting gas. We sprayed starter fluid on the carborater too. Any suggestions??? We need to get this boat around to the marina to pull it. Help Thanks drcoates