I recently acquired a double mantle red/green Rinnai lantern. I took it apart most of the way. I removed the pump assembly and NRV/check valve. I thought the NRV had an o-ring or pip but I didn't see one. When I try to light it, it only stays lit for a few seconds. I opened the fuel cap after a few minutes and there's almost no pressure left so I'm losing pressure pretty quickly. Is there a magic trick to rebuilding one of these that I missed? I've got tons of experience rebuilding a Coleman lantern but not one like this. Also, it came with a Coleman globe from a 220/290 sized lantern. Looking at the Rinnai's burner frame it appears that the Coleman 220/290 globe is just a bit too short. It's also a bit too narrow at the topnof the burner frame. I gather that the original globe had a slight taper at the top and is a bit taller than the Coleman globe? Can anyone confirm this?