AA TX200 MK1....... help/advice

Discussion in 'General Airgun Chat' started by Bellerophon, Feb 22, 2012.

  1. Bellerophon

    Bellerophon Active Member

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    Ok gents recently purchased a pretty mega mk1 TX dressed in a gin B stock and everything seemed fine and then all of a sudden I couldn't hit **** all! So I just dismissed it and thought it was me not been able to master the art of springer.

    Anyway after more time on the range, I concluded something was a miss (not just me). Shots going everywhere. But some would group togethe, occasionally.

    So to the chrono. Well when I last chronoed it, it was 781 fps with JSB 8.44, now it's doing between 691-735 :eek:

    I've just stripped it and what i've found is....

    On the piston the (excuse lack of correct naming of parts) the front main seal (green) feels a bit hard and brittle, also some signs of wear. The piston head looks fine, the spring looks fine too. But on the piston the two seals (black) that sit in recess' on the piston both have nicks in them. So i'm presuming that this is the cause of my dramas. The shaft of the piston shows signs of rust but I can't see how that would cause my dramas as the shaft dosn't come into contact with the spring guide. Well unless anyone knows other wise?

    Now seen as it's safe to presume the above is fubar, well the seals anyway. It's also safe to presume that it's been quiete a while since the rifles been given an over haul. so it got me thinking (very dangerous i know).

    I'd like to short stroke my TX obviously as I'm going to need new parts I might aswell try something new. So anybody know what i need to do this? Or more to the point anybody on here know where to aquire the parts to do it?

    Or if anyones got any other advise i'd appreciate it, I'm pretty certain I've got a mk1 piston as it's quiete large in comparison to the mk3 ones I've seen. Anyone got experience of V mach kits?

    So over to you good people of STB.....


    Cheers K
     
    Last edited: Feb 22, 2012
  2. ellis d

    ellis d Active Member

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    nick murphy's your man, for short stroking and tuning tx's
     
  3. Knockedover

    Knockedover CSFTA Champ

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    Kieran, speak to Mr Gillies and he'll fill you in on the parts and spec used in the build as he tuned it. Since he tuned it for me its probably had less than a thousand pellets through it so I'm quite surprised by your findings.
     
  4. Bellerophon

    Bellerophon Active Member

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    Ok lads thanks for the input, so it looks so far like it's got V mach parts (apart from the piston), now a dumb question, how the hell do i get to the breech seals?
     
  5. steveggg

    steveggg Trainee Grumps

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    Hi Kieran,

    As Vinny said, i serviced this a good few years back, but can't remember all the details, think it is short stroked already (MK1/2) are better than MK3, and fitted with a Shot Master Kit(Bonnie and clyde,Dave Hall) and a Maccari Piston Seal.

    Sounds like the 2 breach seals in the comp tube have gone, order from Chambers, the only way to get them out is using something pointed but they are usually useless afterwards.
     
  6. Bellerophon

    Bellerophon Active Member

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    Looks like its the breech seals then :)
     
  7. Bellerophon

    Bellerophon Active Member

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    Ok here's a little update. Stripped the rifle again and replaced the breech seals, had another look at all the other parts and there doesn't seem to be anything that raises any eye brows.

    Re-assembled the rifle and chronoed it, muzzle velocity with mozzies 751-761 fps, JSB exacts 754-764 fps and Daystates about the same. So consistency has returned, so I decided to put some range time in in the fading light.

    Well it doesn't seem to like the Exacts anymore but seems to favour the mozzies by quiete a margin. So seen as I'm basically 40fps shy of what I'd like to run with the mozzies anyone got any suggestions on how to increase the muzzle velocity. I don't want to go down the new spring route but if anyones got some good experiences of custom springs them maybe i will.

    So I think i'm looking at the pre washer option, so whats your opinions on this? If this is the route to go down anyone got any idea where to get some from?

    Once again thanks in advance K
     
  8. Recoiling Rob

    Recoiling Rob Member

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    Hi Keiran,

    I use nylon washers, fitted inside the piston, infront of the spring and tophat, this gives around 10 fps per washer.


    I also use the hardened steel ring as supplied to fit between the spring and spring guide, again this gives around 10 fps per ring.
    The rings can also be fitted in place of the nylon washers if necessary.

    You can get the steel rings from Aie Arms or Chambers gunmakers online.

    Regards

    grubber
     
    Last edited: Feb 23, 2012
  9. Bellerophon

    Bellerophon Active Member

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    Cheers for the rapid response Rob, so here comes another dumb question. The pre load washers, I was always under the impression they went at the back of the spring? Now reading your reply it seems they go at the front with the piston?

    Also for clarity just have a look at this exploded diagram HERE. Would you be able to point out which part the top hat is? I'm a tad confused (as always).

    Once again many thanks Kieran
     
  10. Recoiling Rob

    Recoiling Rob Member

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    Hi Kieran

    The "Top Hat" is numbered PSW 004/5/6 and fits (screws) into the piston side of the Spring, into the three "dead" coils on the MKl & Mkll spring.

    There is a thick steel washer that is listed PSW 003 that will lift your power too, Air Arms told me that it was a "running in" spacer, and was removed if the gun went over power :)

    The hardened steel spacers that I use as preload spacers are listed as W093 on the TX 200 Mk lll

    The hardened steel spacers can be fitted at either end of the spring, I would normaly fit at least 1 at the spring guide end to aid with wear, but they will also fit inside the piston, infront of the top hat, for setting the power if you want.

    I get the nylon washers from Jeff Skinner (Redfearns) - they are the same as a regular washer but made out of nylon, and these will only fit in the piston side as they wont go over the spring guide..

    I believe that the V mach kits instruct fitting their preload washers infront of the spring, inside the piston too..

    Hope this helps

    rob
     
    Last edited: Feb 23, 2012
  11. steveggg

    steveggg Trainee Grumps

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    Kieran,

    2 sizes of washers are needed and can be Delrin/Brass/Steel of various thicknesses and can be fitted in multiples, to fine tune a gun.

    1 Inside the piston, so infront of the tophat on the piston rod (Smaller internal diameter)

    2 Behind the spring on the spring guide (Larger internal diameter)

    No 1 will add more weight to the piston if you go for brass/steel so tends to slightly dampen the recoil.

    Both will cause the spring to compress more, which could lead to the rear of the tophat meeting with the front of the spring guide and you not being able to get the gun to cock, worse case.

    As you are fine tuning it will be trial and error, generally one 1mm washer will give around 10/15 fps.

    Not sure if there still available but i got a selection of both sizes in various thicknesses from Dave Hall.

    Or you can use steel washers from a hardware supplier and polish them yourself.
     
  12. Bellerophon

    Bellerophon Active Member

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    Cheers gents again for the input, Steve I've found some washers here are these the correct washers?
     
  13. steveggg

    steveggg Trainee Grumps

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    Kieran, sorry i thought i replied yesterday, probably hit the wrong button-old age.

    No that's no good it's the old AA top hat.

    You might be able to get some washers from POK or UKNEIL on the BBS, or send me your address and i can stick a few used ones in the post.
     
  14. w-v-m

    w-v-m Member

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    Missed it's
    My tx has been v mac'd and short stroked, and its now great..............
    at propping up the other guns in the cabinet.

    Its great off a bag on a bench, but for hft, it misses kills it should hit, and hits kills it should miss, or at least thats how it seems.
     

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