Running rich....To big of a carb or?

Ive already went through the steps on adjusting the mixture screws....still no luck.

Here are the factory carb specs " Fuel:Gasoline
New or Remanufactured:New
Number of Barrels:4
Carburetor Flange:Square bore
Choke:Electric
Secondary Type:Vacuum
CFM:750
Fuel Inlet:Dual
Primary Jet Size:77
Primary Power Valve (Hg):9.5 Hg
Primary Discharge Nozzle Size (in):0.035 in.
Secondary Jet Size:79
Secondary Power Valve:6.5 "