"Eddie" AFB carb issues..

What does your oil smell like? If it smells like gas, find out where its coming from

Make sure you are not sucking air in the fuel line......given that you said you can crank for 3 hours and have nothing.....after an extended crank you should have gas, so somethings wrong there......get gas to the carb reliably when its cold........as rumblefish stated, put a thick gasket under the carb to thermally isolate from the intake when its warm

Good luck!