I find it hard to believe that Thumper won't help after you bought a carb from him.
He helped me before I ever bought any thing.He is one of the better vendors here.
I had an issue similar to yours just opposite symptoms.Its hard solving tuning issues on a web board. Can you call someone or
bring it to someone for 2nd set of eyes?
Whats funny the person who actually figured out my issue was BigDad's favorite person...lol