KWA vector won't fire
 

Hi, I have a KWA kriss vector. The gun stopped firing. The bolt will go to the hop up dial. It will place a BB in the inner barrel, but it won't fire. Looks to me like there is no pressure to propel the BB forward. It's noteworthy to add that I replaced my barrel and hop up with EVO II (http://shop.ehobbyasia.com/maple-lea...l#.VIKG48mCVQs) and that I have removed my piston spring hanger roll pin, in order to install http://www.evike.com/products/49278/. But then I changed my mind and placed the Pin back. Only thing that I can think off is if I damaged the piston somehow. Any Ideas?

There's a spring that goes on that pin, did you forget to put hook the spring up to it?

So I have verified the problem. I switched back to stock inner barrel and it started firing again. However, I would get a lot of jams especially on semi-automatic. A single BB would invariably get stuck in the hop up chamber. I never had this problem prior to me removing the hop up set/inner barrel assembly. My instincts think that the hop up chamber is too tight. How do I fix this issue?

sell me that blowback housing you don't want :)

Gun worked, then you messed with it, now it doesnt work.
My instincts tell me you assembled something incorrectly. The hop rubber probably isnt seated properly.