Even though you have cleaned out your tank think about how the crap that is plugging your jets is getting into the tank? It is prolly crap in your gas tank. It might be comming from the gas station you are buying gas from, if you buy pump gas that is. You should get gas from a gas station you trust even if you have to pay a little more.
A Gas Station like Cumberland Farms is crappy gas. Get gas from a Mobile/Exxon Station if you can. If you do not have any around there, get gas from a Costal Station. That is were i get my gas and i have never had a problem with it.......
You could have dirt entering through the air filter. I rode one day at a dusty track and the next the bike would not run. The filter had been fresh but the dust overwhelmed the filter and then allowed dirt to go by.
Once all of your oil on the filter has dirt attached to it, the dirt has a direct route to go into your carb. Check to see if dirt is caked on your filter.
Every time you wash your bike, ie after every ride, you should check your filter condition.