Here are two things you might look at if you think it's a fuel issue and nothing else helps.

Have you checked the filter screen in the carb? Not sure which make or model carb you have. Most likely it's a Tillotson.

When my old 140 was leaning out in flight, I bit the bullet and learned about what is called "pop off pressure" for the carb.
Turns out mine was set too high, and the fuel inlet needle wasn't letting enough fuel through. The concept took me awhile to grasp, but I'm glad I took the time to do the research.

Try a search, and look at this link. [link=http://www.rcuniverse.com/forum/m_1866098/anchors_1866098/mpage_1/key_pop/anchor/tm.htm#1866098]pop off[/link]

Hope this doesn't turn into a Ford_Chevy thing

Lots of machines have trouble from time to time and need attention. Granted, the newer technology carb blocks don't have the bad tendencies of the older designs, but they still work when they're flat etc.

Anyway, poke around and keep us posted on the results_bob