Amamba,

Air lock is fairly rare and occurs in hot engines. By now your engine
should be ready to go.
You indicate that the line from the gas tank to the fuel pump has gas but
that the line from the pump to the carb does not. Disconnect the gas line at
the carb and try to start. If the fuel pump is working gas should squirt out
of the gas line. If it does then you have a blockage in the carb. Remove the
float bowl and see what's sticking. You may need to replace the float valve.
If gas does not squirt out of the pump disconnect the gas line from the
tank to the pump. Gas should flow out. If it does look for the fuel filter
and replace it. If gas does flow then the fuel pump needs replacing.

Dave M.