Won't Take Throttle

I just bought this 2007 Bonneville from a guy. I knew the carbs needed work so I took it straight to a Triumph shop for repair. They took the carbs off, cleaned them said the pilot jets were stuck, repaired them etc...
They informed me that they would have to use an external fuel supply to test the adjustments they made. I got the bike home and cleaned the fuel tank and used Ospho to kill any rust inside. I rinsed with plenty of water and dried it out very good. I then put the tank back on the bike and put in fuel.
It started right up at first. I got on the street with it. It ran OK to about 5k rpm then struggled to get to 6.5k. It sputtered but would get there eventually. I let the bike cruise at 70 to 80 mph for a few miles, no problem.
Then the same thing happens. After shutting the motor off it becomes difficult to start.
Any ideas?

 

I just cleaned the tank but did not check to see if the petcock may have some junk in it. I will search that.