There, My question is; How to clean the.

Hi there, My question is; How to clean the internal lines of the carburetor. I opened the carburetor to fix the accelerator pump which is combined with the float bowl. Now there is no petrol coming out of the fuel line at the throat of the carburetor. (I purchased a new plunger kit and I sprayed carburetor cleaner from one end of this fuel line to other and it came out from the other end, but I'm not sure how clear is this fuel line). This cause the engine stalls and lack of power especially in cold weather. Apart from this, the "O" rings (rubber rings) on the main jet were wear out and the tail pipe was producing black smoke even at idle, so I replaced them but not with the exact ones. Due to this the engine backfires at the intake manifold, loses power and sometime the engine stops. Your help will be really appreciated. Thanks in advance.