ORIGINAL: griesel
I searched tower hobbies and discovered a Dubro Tank Filter which is a filter clunk and looks similar to the OS for a whole lot less money
$2 versus $14.50. I also found on pspmfg.com a clunk with a filter for $4.20. I have a clunk that came with my manual pump from h9
that has a screen filter. There are also some felt pad clunk filters that state they will eliminate bubbles. Changin the clunk is a whole lot
easier than trying to dremel out clearance for tank padding.
One of the most overlooked items to rid a fuel system of foaming is a small "Hopper" tank. A 2oz. tank between the main tank and the engine will do wonders to give better runs.
I have used them both internally on larger models, and the hopper externally on smaller models. Sometimes a 2 oz. tank and a 6oz. tank can be used to replace/supplement an 8 oz. or whatever size you need reference the model. Two fuel-line system or 3 line works. However, You have to fuel the hopper first, with the hopper vent being the receiver of the master Tank's fuel. Pressure goes into the Master tank. Be sure you plumb so the clunk can move in the hopper as well as the master. If the clunk cannot follow the fuel, you will come up short when the tank gets low.