KWA ATP service life

Discussion in 'Gas Powered Guns' started by K.R., Jul 13, 2021.

  1. K.R.

    K.R. Member

    33
    2
    Clemson
    I have a KWA ATP purchased in 2015 that has stopped cycling properly. With a freshly filled mag it would shoot but not push the slide back enough to load the next BB. After a number of shots it would cycle a bit better but still only ~85% success rate. The gas would run out after about less than 2 clips then it's same thing all over again. I've checked the nozzle assembly, oiled everything and mag's internals but the problem persists. I could start replacing parts but there's no telling if it'll all still be in vain. I'm wondering if the pistol is at the end of its service life and there's not much worth fixing? Anyone has experience with this pistol can share how long it lasted for you?
     
  2. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    You may have a cracked nozzle.

    Cracked nozzle bleed off the pressure to fire a bb correctly. You will not see a crack unless you take the nozzle out and "flex" it.

    I have other KSC products that are going on 13 years of use as trainers. They can last a very long time with "proper" maintenance of which what is passed around in Airsoft as the Gospel for proper care is indeed wrong in so many ways.

    With the ATP...do NOT use Green Gas just dry propane is fine and grease or use heavy oil for the friction points for wear mitigation - rails hammer group...etc.

    Silicone Oil (aka Siloxanes) is worthless for metal lubrication in Airsoft.
     

  3. GrimWolf0770

    GrimWolf0770 Active Member

    248
    62
    Pittsburgh area
    What dose guges recommend? Maybe fish oil?X~X
     
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  4. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    MolyB grease...
    Right Whale oilis...j/k.

    [​IMG] I bought one tube 7 years ago...maybe I have used 1/45th of it...specifically I like this:

    " This product features a low coefficient of friction immediately upon application, without burnishing."

    Wipe on a thin film on the rubbing parts and then it gets really smooth.
     
    Last edited: Jul 14, 2021
  5. K.R.

    K.R. Member

    33
    2
    Clemson
    Thanks for the suggestion on the nozzle. I tried to flex it and examined it closely, as far as I can tell there isn't any cracks.

    The other thing I suspect is a weakened hammer spring, but the process of replacing it is quite involved and there's no guarantee it would fix the problem...
     
  6. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    If there is no issue there...is this happening on the same bottle of gas our is this working like this on "all" gases and at all temps?
     
  7. K.R.

    K.R. Member

    33
    2
    Clemson
    I've tried two different bottles of green gas with similar results. I used the same bottle of gas a year or two ago on the same pistol and it worked fine before...
     
  8. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    There is a rare occurrence, but it can happen in an ATP.

    ATP and KSC/KWA Glocks all share the same internals. These units are based on a design from ~1997, made by the Taiwanese factory Yih Kai.

    The seals are a low grade rubber. Do not use Green Gas with high Siloxane (aka silicone oil) content in the gas. In fact you shouldn’t use any gas with an oil in it for it will ruin your range, among other things on a Yih Kai product. Just run normal dry propane…its cheaper and better for your gbb.

    The issue is the rubber seals in these products can “dissolve” when exposed to Siloxanes. This leads to leaks on the mag base seals. The dissolve material can work it’s way and adhere to the pin valve on the gas release, thus gumming it up. This can cause weak shots and/or leaks from the mag in this area.

    You can try new KSC valves to see if your issue goes away or you can try cleaning them.

    However, I highly recommend a 3 sided valve key for this endeavor.
     
  9. K.R.

    K.R. Member

    33
    2
    Clemson
    alright I'll try a mag from a different gun when I can get my hands on one and see if the problem is with the mag release valve.
     
  10. K.R.

    K.R. Member

    33
    2
    Clemson
    Just posting this for the record in case someone is reading this thread in the future to troubleshoot a similar problem. I replaced the hammer spring and the sear spring and that solved the problem. I suppose the springs just got worn out over time.

    On that note — how do you all do long term storage for your GBB pistols to avoid wearing out springs?

    #1) With trigger cocked back and magazine in the gun
    #2) With trigger depressed and magazine in the gun
    #3) With trigger depressed and magazine out of the gun

    I've been doing #1 and #2, but it seems that to avoid wearing out the springs in the trigger block #3 would be ideal? What are your thoughts.

    Ironically, right after I fixed the springs, the main seal broke after a bit of testing, so the pistol is out of commission again. I guess all these problems come with old age... heh.
     
  11. richman992

    richman992 Well-Known Member

    1,533
    98
    Rochester
    Mag out of gun, I pull the trigger to release the hammer spring tension. Then I personally ever so slightly pull the slide back to re-engage the trigger but not the hammer. That way the trigger bar spring isn’t stored under tension. I run Marui but I remember doing the same with my KSC/KWA Glocks.
     
  12. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    And leave a hint of regular propane in the mags. ATP do not like Siloxanes...it degrades the seals...and on that note. What are you calling the "main seals"?
     
  13. K.R.

    K.R. Member

    33
    2
    Clemson
  14. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    ^AKA Piston Cup. Again, US distribution fail...these companies are run by people that know nothing of this industry (I know, I worked for one...)

    How did your piston cup "break", did it tear?
     
  15. K.R.

    K.R. Member

    33
    2
    Clemson
    About 1/3 of the cup chipped off, here's a picture https://bit.ly/3i8t4Vk

    Granted I was testing out something by blocking the nozzle outlet, which may have increased the pressure rise rate, but shouldn't have increased the pressure magnitude by much. I'm thinking it was probably more so just an old piston that's about to go...
     
  16. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    The cups are rubber...most likely it dried up, cracked and then came apart.
     
  17. K.R.

    K.R. Member

    33
    2
    Clemson
    KWA just told me that they ran out of main seals so I won't be able to order any, yikes.

    Do you know where else I can get one that will fit the ATP?
     
  18. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

    8,123
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  19. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    If it doesn't say Model "XXXX" I wouldn't risk it.

    Plus...KWA never made a colored "OEM" piston cup.