Marui P226 valve knocker problem
 

Main issue: gun doesn't dry fire*

Problem is replicated by:
-inserting an empty magazine
-racking the slide with thumb on the slide release
-pulling the trigger
-gun doesn't dry fire

Not sure if this issue pertains only to me, but basically in my TM P226 with Guarder kit and Guarder chassis assembly, the valve knocker doesn't lock back when a magazine is inserted.

I cock the hammer, insert the magazine and then release the magazine, and I see that the valve knocker is still in the forward position. this means that when the trigger is pulled, the hammer will not hit the knocker.

diagram 1 (hammer cocked, magazine inserted and removed, valve knocker still in the same position. the gas valve doesn't push the knocker back to lock it)
https://i.imgur.com/sgNO39b.jpg

diagram 2 (hammer cocked, valve knocker can be manually locked back with finger)
https://i.imgur.com/tATkk5D.jpg

*if I manually engage the valve knocker lock, then insert the magazine, rack the slide with thumb on the slide release, pull the trigger, the gun will continue to dry fire until out of gas.

Are you only visually inspecting the valve knocker or are you feeling it when you dry fire and putting your finger on it to feel if there's any movement?

The valve knocker is supposed to be free moving to accomodate a magazine change...