starting at the carb,remove the fuel line and then turn the motor over while blocking the exhaust port, it should pressurize the fuel lines and squirt fuel out. it it does not then replace the line to the carb and trace back to the next fuel line junction e.g. fuel filter or tank and repeat turn over process keep repeating the process until it does squirt fuel, from that point to the carb is your blockage. BE CAREFUL not to squirt fuel towards eyes or heat sources. Also check for collapsed lines or fuel tank not sealing.