Interesting replies. I think I'll give the felt clunk a go. It fits easily into my Sullivan 14 Oz round tank, but wouldn't into the Hayes Slimline 14 Oz tank I had lined up.

I am using a nice in-line filter between tank and carb. That should deal with any felt fibres.

I found it after nosing around at my friendly local motorcycle shop. It has a crystal clear heat resistant body with an ultra fine filter mesh. It is used on scooters and the like, and has a much larger surface area than typical model engine filters. It looks to be well made - it is made by in the USA in Ill. by Plastisonics, if I can read the brand correctly. Cheaper than your better model filters too!

They also do a smaller in-line filter with a "sintered brass micro-ball" type filter media, like Du-bro use on their "filter" clunk. I bought it as well, but I am a little wary of it though - I am always scared a little peice of brass will break free and cause a blockage somewhere, or worse [:'(]

I have any adverse experiences I'll post again. Thanks to all who posted

fiery