Chainsaw Repair

I've seen it a lot lately where it will be the upper flapper diaphragm that will be bleeding the pressure off.  I don't know if they get a little pin hole or if the cover gets warped but they bleed down when testing the pop-off pressure.  You can put grease on the needle and hold it down with your finger and the carb will still bleed pressure.  It seems to happen more on carbs with one screw holding the top cover down.  Most of the time a new flapper and gasket will take care of it.