Steve, If you decide to media blast the frame be sure to protect the chassis number from being obliterated. I have seen a couple such. The media used on my frame (50 years ago!) was powdered red brick. It did the job without disturbing the metal. After pointing out the chassis number the shop said t...

Skip,
Is it possible the gas tank filler cap is not venting and the pump is stopping when it pulls a vacuum on the tank. Later, air leaks in and then the pump works.

Bill Traill