CYMA CM046 Ak47 - How do I Downgrade the Spring with Electric Blowback Gearbox

[Bar1975]

Hey guys.. i just purchased this AEG and absolutely love it so far. I didn't realize how powerful it was and as a result will need to downgrade the spring so that i can use it on the field i play at. (<400FPS with .2g)

Anyways.. I've got lots of experience working on Version 2 and 3 gearboxes but i have zero experience with this electric blowback mechanism. I started to tear down the gun last night and just had to stop. I have no idea what I'm at right now. I can't find ANYTHING online in regards to changing out a spring in a gear box that also has this EBB feature. I believe it's a pneumatic blowback so it's all built into the gearbox itself. I don't believe i can simply crack open the gearbox without first taking apart this EBB.

Does anybody have any references or advise on this?

[JerryMcGoulBerry]

The AK should be shooting under 400 FPS and there should be many tutorials on YouTube.

[Rusty Lugnuts]

I'll try to be helpfull.. IF your only say 15 to 20 fps over, the spring will settle in and fps will probably drop enough, after 500 or so bb's

[MaciekA]

Are you sure it's G&G-style pneumatic blowback and not a mechanical blowback (i.e. piston pulls back a tab external to the gearbox) ?

[Bar1975]

its a pneumatic system..

http://www.youtube.com/watch?feature...&v=yqeX6Tido8I

i really want to downgrade the spring and clean up the AOE but too afraid to screw with that gearbox until i see a video or something describing the steps..

i've been searching for something now for days..

[R.I.T.Z]

http://www.mechbox.com/

[MaciekA]

Originally Posted by R.I.T.Z

http://www.mechbox.com/

Damn, I'm amazed mechbox.com still hasn't updated since their supposed refresh, it's now been a year ..!

[MaciekA]

Originally Posted by Bar1975

its a pneumatic system..

http://www.youtube.com/watch?feature...&v=yqeX6Tido8I

i really want to downgrade the spring and clean up the AOE but too afraid to screw with that gearbox until i see a video or something describing the steps..

i've been searching for something now for days..

Well, if you're adventurous to handle AoE then you can handle a pneumatic blowback... Just take pictures with your phone at every step as you take it apart, pneumatic blowback is never that complicated, if you screw it up you can always disable the blowback by throwing in a standard cylinder and lose nothing. If you can handle rebuilding this gun w/ AoE and everything, you can pretty much handle anything afterwards. Worst case, you just post pictures here until it's back together...

[Bar1975]

So after further tinkering around with this gearbox (CM 02B) I realize that it not only has a pneumatic blow back system but a RECOIL system as well. There is an open hole in the top/back of the gearbox.. i can see the spring from the top of the gearbox.. the Piston looks like it has a groove or section cut out of it as well..

There is a metal arm that is bolted to the gearbox body and attached with a spring to the front receiver'. To separate the two halves i need to unhook this spring.

what the hell did i buy!!.. if i can't tinker with a gun then whats the fun damm it.