Well the carb guy came to his shop on a Sunday for me. He had said over the phone probably contaminants, I watched him take the carb apart, sure enough, some small pieces that looked like metal shavings. He put in a new needle and seat just in case the old one was scarred, cleaned and blew it out, new filter, and ran it on the engine while I watched. Took the carb back to work where the truck was, and it runs great. Don't know where the sediment came from, new tank and lines, he said it doesn't take much.