There is a translucent fuel line BVM sells that is much softer than Tygon for inside fuel tanks. It also will stretch some once it is in fuel so cut it a 1/2" to 1" shorter.
You can find it located on BVM's website..if you go to JET ACCESSORIES then KEVLAR TANK ACCESSORIES you will find it $6 for 3 feet. This will allow your clunk to move more freely.
BC