I have recently rebuilt the carb on my McCulloch chain saw. The carb is a ZAMA (Japan made). The saw runs fine for a short while and then quits. Subsequent attempts to restart are futile. The carb seems to be loading up. I notice excessive fuel at the exhaust. Could I have put a gasket in backwards? I have no diagram of the carb or gasket placement to refer to. This carb uses a plastic disk that rides on the needle valve assembly (looks to me like some type of float device). If anyone has a diagram of this carb, I would greatly appreciate a copy of it so I can put this thing together right. Thanks in advance!