Yard Vac only runs on full choke
I just "refurbished" a pressure washer that had set for a while.  I cleaned the carb and got it to where it would start, but it would only run with the choke on. 

Through some online research and trial and error, I determined that when choked, the fuel takes a different route through the carb.   I had to remove the main jet and associated parts, soak them in carb cleaner for a while and clean all holes with a wire much finer than a paper clip.  I could only find carb cleaner in a spray can, and I didn't want to purchase a whole gallon of chem-dip, so I just used the spray can to fill the bottom of a glass jar which worked fine.

Once that was done it ran better, but only for a few minutes.  On a hunch, I tried running it for a while with the gas cap off, and it worked.  Turned out the vent hole in the cap was plugged by a spider or who knows what.  After widening the hole a bit, it ran for the rest of the day.  

Forgot to mention: Don't get carb cleaner on any of the rubber seals.  It makes them expand, and when they dry they will shrink back to shape, but it's bad for the rubber.

Not the most exact answer, but hope it helps!