CA m15a4 sportline

[MLA PRO]

So im trying to fix my friends gun. The original problem was that the stock 8.4v (fully charged) wasnt powerful enough to turn the motor. I tried adjusing the height and that did nothing.

Today I took his gun home with me and just for kicks, plugged in my LiPo. The gun actually fired. I then tried my 9.6v and it fired. I also opened up the GB and everything was fine. The only weird thing is, is that when i use the 9.6v with it, after every shot i hear something vibrating inside the GB. It didnt do this with the LiPo.

Is this just a case of a faulty battery? I dont understand how a non-upgraded gun wont shoot with a stock battery

[Crono0001]

His battery may be shot, ask him if he overcharged it.
The 'vibrating' you hear- does it sound like gears turning?  It may be your anti-reverse latch.

[MLA PRO]

Thats what i was thinking. But then i payed more attention  and it sounded like it was coming from the spring.

[axisofoil]

bad shimming.

[nynone]

My sportline has the same issue. Once i get the gearbox reassembled (broke my piston due to idiot assembly after shimming the gearbox), I can let you know if it still has the same issue. I think it's really just the spring giving a little twang from the compression it's under. If it's that, a ball bearing piston may help (as they let the spring spin naturally during contraction and decompression, but I'm sure you knew that ). It could be the shimming, but if the sound seems to be coming from the spring, I'd strip out the gearbox and fire it that way to get a better visual on it, as well as being easier to pinpoint the sound.

[steyraug223]

Check his wiring and fuse. Depending on the wiring and fuse there could be an insufficent amount of power getting to your motor to cycle the weapon, however this would be overcome by a LIPO and a 9.6v

[nynone]

Sorry, i meant a ball bearing spring guide or piston head I'll also update you tomorrow to let you know if a shim job would be the solution

[MLA PRO]

I figured out that its the battery. I tested it in my KWA and it didnt even turn the motor. And ill tell him to buy a ball bearing spring guide.

[Zuul99]

This could be one of two things. I had the same problem with the same rifle. The first is shimming, if it has been opened and worked on. The latter is that its your (his) motor. If its a High torque Motor than it might require some extra juice, My CA sportline has an AMP motor and on the box it says power output: 9.6v. So in order to cycle you need that amount or higher. To check if it is the motor feel and see it the wiring get hot because that means its drawing power but its not enough. Ball bearing Spring guide and piston wont help either because those are not the parts involved with the cycling of the gears which is were your problem most likely manifests. Also check the sector gear if it has not been replaced, Its pot metal so it wears very fast, and the worn teeth apply unnecessary friction.