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Piston rod not latching.

Posted: Mon Jan 16, 2017 1:44 am
by Kelvin
Hello, Newbie here.
I decided to re-lube and polish my TX-200 MKIII for the first time yesterday.
Now my piston rod will not latch.

What I did:
I removed and replaced lube, polished spring ends, and trigger.
This rifle had no spacers, just spring,top hat, tube guide and a washer between the tube guide and spring.
The washer had a nick on its edge so I polished that out while polishing the spring ends.
The trigger seems to work fine outside the rifle.

Please help.

Re: Piston rod not latching.

Posted: Mon Jan 16, 2017 11:18 am
by Bosun
Hello Kelvin,

I wish I could help. I had the same problem a couple of years ago, but can't for the life of me remember what I did to fix it. I'll do my best to wring out the grey matter and post if I come up with anything. I know it sounds obvious, but If the trigger is functioning OK, presumably it has to be the piston not travelling far enough.

Re: Piston rod not latching.

Posted: Mon Jan 16, 2017 3:52 pm
by Kelvin
Thank you, Bosun.
I might order a tune kit that includes the spring, that should correct my problem.
But, I still want to know what I did wrong.

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 4:06 am
by Kelvin
I removed the top hat, and it still will not latch.

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 8:47 am
by Bosun
Good morning Kelvin,

I may be talking a load of eyewash, but I seem to recall that while the trigger appears to work "off-rifle", it needs to be re-set before re-assembly.

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 8:48 am
by pelletcaster
Kelvin wrote:...What I did:
I ... polished ... and trigger...


That sounds like you disassembled and reassembled the trigger.
Check trigger weight (screw) - maybe too light.
Or stage 1 and/or stage 2 scews set not properly.

Did you pull the trigger after installation before trying to cock?
May be it's still set.

If you try to cock outside of stock - how does the spring behave?

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 8:51 am
by Sake-san
From what you describe I would look at the following and in this order...
1. Ensure that the trigger adjustments (esp 1st stage and weight) are sufficient for the sears to engage, try increasing the adjustment on both
2. Check that front stock screws are not fouling the cocking arm and preventing sufficient movement, try loosening them off a turn or two
3. Check that the compression tube end cap is not loose/undoing

Good luck

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 5:36 pm
by Kelvin
The rifle will fire now.
I left out the top hat, tightened the retaining screw, jerked on the cocking lever(At the end of the cocking stroke) and used strips cut from a plastic bottle to shim the latch plate.

The rifle was working fine before I started this project.
I still do not know what I did wrong.

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 6:50 pm
by Sake-san
Did you try the potential remedies suggested by pelletcaster and myself?, I suspect that at best you have masked the real issue...

Re: Piston rod not latching.

Posted: Tue Jan 17, 2017 7:25 pm
by Kelvin
I think you are right Sake-san,
The front stock screws are not touching the cocking lever.
I have not tried the trigger adjustments, what is the proper adjustment procedure from scratch?
I can not feel much difference from 1st to 2nd stage on the trigger.


Thank you for the help.