Cyma Ak74u Gearbox Q's.

[Swordfish]

Hi,

Just bought a cyma Ak, very nice gun Imo. It was however, overpowered, so I opened it (the only other gun I did Gearbox work to is my p90) and replaced the spring with a guarder sp100 spring.

Unfortunatly the first time the GB was opened, it decided to explode all over the place. I have now resassembled the offending gearbox, however, I know how two shims left over. I could not for the life of me figure these out.
The gear teeth seem fairly well aligned with each other and the piston.
I have watched a few guides on shimming and they seem a bit vague, I dont really have a clue how tight everything should be etc. Anyone help me out?

Secondly teh spring guide is plastic so I want to replace it with a metal one, would an ICS V3 guide work in this box? Its a V3 box but had heard ICS do things a bit different.

Also can anyone point me to were I can buy some shims? Cant find them on zero one.

The gun is shooting ok, and sounds ok, I was going to use it for a game or two then open it up, change the spring guide and then shim it, just need help with shimming!!

Thanks!

[North West Outpost]

Re: Cyma Ak74u Gearbox Q's.

The shims will deffo have come from one of the three gears. With the gear box out push the ends of the gears from side to side. There should be a tiny movement but not too much. You should soon see which axle they came off of.

It probably exploded for one of two reasons, either you didn't hold the spring guide in place when you opened it up. Or you didn't release the pressure from the anti reverse befor taking out the screws.

Secondly I am selling a new spring guide, scroll down to the Vortex bearing spring guide it will fit in your gear box. Let me know if you are interested. I should have some shims in a week or so.


http://www.zeroin.co.uk/showthread.php?t=62806