Thanks Craig,
I'm talking about the little ring that the chimney pops into.Without it the liquid will pour out the top. When it swells it flies out when I go for rebuild. At first I had no idea where this mystery ring came from when it evidently came out of the Kayfun but wouldn't fit anywhere.. Thus I realized that it would of swollen. I have now run out of spares and tried drip tip rings and all sorts but to no avail.
Hope I can get something but other than this the Kayfun is fantastic.. I just love pluid in the Kayfun. But looks like I might be stumped for now.