mg1980brat

I've recently narrowed down my car issues to my carburetor. I have a parts Brat so i took that one out and popped it in mine, all the seals are new but it is a different version. And now gas comes of an odd area so i was going to put the old one back in, but theres a loose lever i can't figure out, can someone tell me where this is suppose to be connected with. its the part where my finger is.