Suggestion
get a propane torch turn the gas on don’t light it run the nozzle around all your fuel lines next to the carb not the throat with the engine running if you have a suction leak somewhere the propane will make the motor rev higher don’t worry you won’t blow up
check that your fuel tank is venting
if it’s an old fuel line from the tank spending the money and buy a new one I don’t think your issue is worth taking to a shop check the idle setting as well it sounds like an easy fix
and throw some SEAFOAM in with your gas
hope this helps a bit
Cheers
Biteme