[exwestracer]

Originally Posted by Macbuick

So, if i understand well : if the blades are fully opened by the linkage, the air doors should open easily, ....is it by the vacuum/airflow created by the engine when running?

I noticed that my air door linkage was stuck ! Perhaps was the problem there!?

Thanks again
David

There is a piece of linkage that holds the air doors shut unless the secondaries are open. You have to have the throttle blades WOT (or close)for the air doors to unlock. From there they should operate freely. If the throttle is WO and the air doors are still stuck, yes you have a problem.