I added that teflon chain lube in the fuel/oil mix during our summer.
Seemed ok, sounded less "metalici". That was 6 or 7 months ago, still going strong. Due for anothr "fix" cos ya only do this on occasions, sort of a "treatment" to line the cylinder with something on a HT btw.
How much did I add ? ( I am not a purist)
Well, there was about half a bootle left so I added the lot in half a tank of fuel.
Large is correct in saying you can insulate the fuel line to keep direct heat away. Some cars have the same prob. when a carby is situated above the exhaust manifold or the fuel line runs close the some part of the exhaust.