Assuming it's the original Avenger, looks like a spyder, but in layout it's more like a Raptor or F1.
You have to pull the bolt linkage out of a hole in the top of the body. To start make sure the gun is uncocked. Unscrew the velocity adjuster and find the spring guide (metal shaft that's inside the main spring). It's threaded on the end. Take the main spring out, it's holding the cocking knob in place. Pull the cocking knob out, it's holding the linkage in place. Put the spring guide into the small hole on the top of the body and thread it a few turns into the linkage pin and pull it out. Everything should fall out the back of the gun at that point.
The valve pin is probably jammed open in the valve. Common issue, comes from dry firing (shooting with no air) too much, puts a dent in the back of the valve. Once you get the valve out you can work the valve pin out and a little filing with a needle file, or some careful drilling with a small drill can fix it.
David Johnson, AKA Fubarius.
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Last edited by Fubarius : 10-19-2010 at 08:03 PM.