Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Have you checked the flow through the needle valve and float passage?
Linkage is not problem,but not enough fuel getting through the fuel passage.
The needle valve and float control the flow into the bowl.
Here is Google search,the second item should be service manual PDF. You can down load it.
Here is a basic, easy ,carburetor breakdown. It is not yours, but all carbs are built alike.