Small Engine Troubleshooting Problems? Ask a Mechanic Now.
The carburetor needle valve is the usual culprit , which is controlled by the float. What fuel pump type do you have? An electric pump that does not shut off, can over pressurize the float and needle.
I don't have exact diagram, but here is link to a basic carburetor, Your's is similar and float and needle valve are accessed the same. Your carburetor should look like the above link. The lower link is the diagram of basic carb.
I was working on it! See it above your response!