Engine only runs in choke

Hello,

we have a problem with our lawnmower gasoline engine. We can start it, using the choke. When releasing the choke, the engine dies.

We tried cleaning the carburator, but without succes.

We were wondering if it is possible to say if this is a problem with the mechanical setting (spring tension, idle, ..) or if it is a problem concerning old outworn tubing, carb, ..

we made a short video to illustrate the problem:

https://drive.google.com/file/d/0Bw5IMQj...