I was cleaning the piston and piston bore today. I took the spring and guide off to clean the gas valve assy. When replacing the exhaust valve assembly, I notice that it had a sort of hood on the guide inside the cylinder. Does this hood inside the gas cylinder cover the barrel ports, or should it be turned so it is on the under side allowing gasses to come into the gas valve assy unabated. Does anyone know what I am talking about? Any help would be appreciated.