Ok you have got something wrong.
Found a parts breakdown for it and there should be 2 lines coming out of the petrol tank.
one goes to the carb lower right ( fuel inlet ) and the other goes to the primer bulb ( return )
The line on the top of the carb should go to the primer inlet.
Now the primer has a one way valve in it so check that you have the lines the right way around.
There are only 2 fuel lines in the carb so if you are still stuck then slip off the air filter and post some pictures.
If you do not alread have a copy download the Zama Service manual which will make things fairly obvious.
http://www.zamacarb.com/pdfs/TechGuide_2007.pdf