Fuel lines most certainly should be clamped at every connection. In my 
opinion, every two years is a bit too often to change all of your fuel 
lines, but this depends on the conditions they are subjected to. Inspect 
them closely every year and replace when they start to deteriorate. I'd say 
it would be a good idea to replace them every five years whether they need 
it or not.

-Mark McCulley

----------
My understanding is that these lines don't
need clamps, but I put them at the fuel tank and the carburetor just to be
safe. The counter guy at ORW suggested that I change my fuel lines every
other year, as most VWs that burn up do so because of cracked fuel lines
(IHHO). Is this an appropriate interval for changing fuel lines, or should
I do it more often?