you know what the disturbing part is i found no O rings when i took the carb out. how do you explain that!! after i installed the carb it still feels a little loose. now that screw that you mentioned, what is the purpose of it? I will take some pictures today of the carb and i will show you what i did!!I am so desperate right know i am willing to ship you the whole truck i will pay you to fix it if you are willing!!!