I asked George if he had tried a BD cap on this Primuus 71's adjustable burner ..... Well, yesterday i recieved a 71e with the same adjustable burner. Sadly the little retaining tab that can be seen in the picture raises the cap from its seat, this allows the gases to escape from around the bottom rim.
Here are some additional photo of the fuel filler cap of this stove: Originally the threaded hole on the inside of the cap would have had a brass screw to secure a rubber washer/seal. This screw was missing on this stove but the stove still operates with a replacement washer. This washer has been exposed to gasoline vapour for many years and it has swollen, producing the convex domed cap you now see. It has no effect on performance and the stove still operates as intended. Best Regards, Kerophile.