briggs & startton quantum 35 mtd wont stay running?

my mtd push mower with a quantum 35 briggs & stratton it will start but then dies right away. if you leave it set 4 a few minutes it will start again but not stay running.i checked spark plug, checked the gas line to see if gas was going through it, sprayed carb with starting fluid did not help, what should i look at next?
make / model 118-084r145/ai148b
here was the answer i got and did 2 time with no luck.
Time for a thorough carburettor clean, Ron. Not to difficult on these, just don't use any rags when doing so....use a proper carb cleaner from an aerosol and compressed air if you can to clear things out. The Quantum's also had dodgy fuel taps too.

cleaned 2 times no luck still starts and dies what else can i try next?