2008 173cc self propelled won't stay running

I thought it had to be the carb so I ordered one from Ebay for $13 bucks and installed it with inline filter and new primer pump. Same thing happens, to keep it running I have to continuously pump the primer. I was guessing with the placement of the assortment of gaskets that were supplied but I don't think I am blocking any areas that need an opening. A diagram of engine parts or assembly would be beneficial.

Any idea? Any pics?

need model & serial numbers from tractor or mower & all numbers from engine & engine manufacturer. an original OEM Cub Cadet carburetor will be more than $13.