Gas tube lever?
The gas tube lever on my Norinco AK comes loose after firing about 26 to 27 rounds.
How can I fix that?
Check to see if your lever is bent. Next check to see if the retaining pin is loose. If the lever is bent the wrong way (aka the nub on the side of the lever is not sitting tightly in the detent) simple push the lever up to the "release" position and grip the lever with a vice grips and gently bend it SLIGHTLY to the left (or towards the other end of the receiver). It may take a couple of bends to get it right don't rush it or you may break the lever. Now If the pin is loose simply tap the pin into place. Hope this helps.