If it is an old Tecumseh engine, the carburetor will have a float bowl and the fuel tank will be above the carburetor. If it is a Briggs & Stratton there will be no float bowl: the fuel tank will be attached to the underside of the carburetor. Or alternatively, just look at the engine itself: does it have a red anodized aluminium plate on it headed "Tecumseh" or "Kirby", or does it have various stickers on it saying "Briggs & Stratton"? My comments on whether the engine is any good would depend on which of these two brands it is, and how old it is. Also, how much power it has depends on which model it is. Tecumseh rotary mower engines are commonly either 2.5 or 3 hp. Briggs & Strattons used on Victas are commonly 3, 3.5 or 4 hp but may be more depending on model. Both Tecumseh and Briggs engines have long series of numbers on them which tell us exactly what model they are. On the Tecumseh it will be on the identification plate. On a Briggs it will be stamped on the blower cowl, near the cylinder head.
When we are clear on what engine it is, we can talk about how to make it go.
