so today i get my 20 oz co2 filled come home cock my sentinel ts, screw in the tank but hopper on n whatnot, go out to shoot, marker goes into full auto n uncocks so i recock shoot n it goes into full auto again n uncocks, its not the tank because i tries my friends n it did the same thing, i gave it a good cleanin n lube after but did not shoot it again, advice would be helpful, thx
Your cup seal is the black part of the pin. It is located inside the place where you adjust the velocity. Unscrew the velocity thing from the front of the marker and check the black part around the metal pin. It's at the end of the spring. I have seen one crack before. AM will replace it for you...they are great about making problems right. Another thing i would check is that you can pull the white piece out of the velocity adjustor when you have the thing unscrewed. The o-ring should be in the back groove. Sometimes they get put in the front for some reason. What it does when it is in the front is cause a vacuum behind the ring. The white part will not move when you change the velocity, so really the velocity is not changing at all. If the velocity is too low, the gun will not recock sometimes. Check all that stuff and if it still won't work I'm sure it can be corrected.
I meant the barrel side groove. It is deeper than the one gun side. If it's in the one gun side, it is harder to move because it is jammed in there. Sometimes it will still work in the one gun side. If there is an o-ring in both grooves, that is not good. Then it will not move at all. It's weird how some things affect some, and others don't. Let us know when it is all resolved what the problem was.