LCS Air Arms LCS SK19 Magazine not rotating and lever not working after first shot

[Hance Rampersad]

I have a problem with my LCS SK19 after following the Airguns of Arizona seal replacement video:-
1. The gun fires once only after it is re-powered .
2. Upon re-powering the mag lever gets stiff and locks the rotation of the magazine ( as it suppose to be).
3. After first shot , the trigger stops working, the mag lever loses power and the magazine can rotate without opening the lever.

I suspect the problem must be some type of alignment with the mag lever , rotation of the magazine and power/air being driven to rotate the magazine .

You can see a short video I did below.

Can anyone assist ?

Thanks in advance

 

[DonEnzone]

That lever is supposed to stay under pressure as long as the gun has air in it, regardless if you're using it or not. From the looks of it, the lever is moving freely, the same way it would when gun has no air in it at all. But obviously there is air in the bottle in your case. So somewhere along the line the air refuses to flow into the mechanism after that first shot.

If it was solely a magazine/lever alignment issue, I imagine the trigger would not be affected, and the gun would still discharge. The fact that it doesn't means the gun is acting as if it was empty, and the trigger is not being "reset".

I suggest you start checking from the source (the bottle) all the way to the main block step by step. it would help if I had an exploded view so we can see exactly how the air travels through the rifle. Because Im pretty sure the air splits off into 2 directions after it exits the plenum. One to the valve, and the other to that lever/rotation mechanism.

 

[DonEnzone]

I also noticed that your reg pressure remains stable at 140. So there is air present at the spot on the block where the guage is located. So I guess the problem lies beyond that point somewhere.

Does the mag rotate as normal during that first shot?

 

[Hance Rampersad]

I also noticed that your reg pressure remains stable at 140. So there is air present at the spot on the block where the guage is located. So I guess the problem lies beyond that point somewhere.

Does the mag rotate as normal during that first shot?

Thanks for the detailed response. The mag does not rotate with the first shot. My understanding is that the Mag rotate with air pressure , the mag lever also works with air pressure.

 

[Hance Rampersad]

Further to the above, air goes to the mag lever when first pressurized, after the first shot however, the mag lever moves freely ( no pressure).

 

[Pale_Rider]

Sounds like the indexing spring is bad. Look at this video explaining the indexing in the huben k-1 (37:08-47:02). For reference the huben k-1 and sk-19 have a very similar valve/mag system.

 

[FelixS]

Also, you can check Nate's video that has a bit more detail:

 

[Pale_Rider]

If you fast forward to 26:40 in the LCS video (mentioned above) you will see the mag indexing parts. That’s where you’ll find your problem.

 

[Hance Rampersad]

Good Morning Gentlemen, first of all thanks again for all support. Your posts lead to success with restoring magazine functionality. I did a test run and everything works well including the auto. The problem was the second valve under the magnetic cover, it need to be precisely align with the internal air channel , tightening too much will lock of air flow to rotate and power the magazine.
I however have one issue with air leakage from the small screw at the top of the magnetic cover . The exact spot shown in this diagram. From research it appears to be a common problem , but I have not been able to find a solution online. Thanks in advance again for any help .

 

[Frito169]

Small seal behind the screw