I wanted to update everyone on this problem.
Today, I picked up the MH because I've got a camping trip planned for Friday. They completed two thirds of the fix. The fix consists of three things. 1) A recirculating fuel line that creates a loop where the fuel can condense and remain a liquid to prevent vapor lock, 2) A heat shield to prevent engine heat from heating the generator and line too much and 3) a re-route of the existing exhaust from under the fuel pump to the back of the motorhome.
They did #1 and #2 but they didn't have the tail pipe to complete #3. On the way home today, I didn't notice any clacking sound but will give this a full test on Friday. Wish me luck.