Chainsaws

I have a PP4218AVX that was running. I was using the chainsaw to cut a big branch that had fallen in my back yard, one of the fuel lines had rotted through and was leaking so I replaced it, I pulled out the carburetor because the line went into the fuel tank. When I replaced the fuel line and put the carburetor back in I cant get the chainsaw started. I am not sure if the fuel lines are hooked up incorrectly or the carburetor needs rebuilt or what. I have a spark. Any help is appreciated.