M4 shooting full auto when set to semi-auto

[SinfulPain]

My JG M4 is currently shooting full-auto on semi-auto at times, which is a little annoying. I can still shoot semi-auto, just via trigger control, but it would be nice to not have to rely on that all the time. Anyone know how to fix it, or what the problem could be?

I haven't taken it apart yet, and don't want to, especially if someone else knows how to take it apart and fix it for trade/free/barter, and doesn't mind me watching them, so I can do it in the future, when I want to modify my gun.


Thanks
~Brian

[AxisOfOil]

Semi-auto cutoff lever is the location of the problem. Likely it is sticking or broken.

Could be caused by the spring on the outside of the gearbox on the selector plate popping off. Or poorly lubricated internals in the gearbox. Or if the lever is bent/breaking.

[SinfulPain]

Semi-auto cutoff lever is the location of the problem. Likely it is sticking or broken.

Could be caused by the spring on the outside of the gearbox on the selector plate popping off. Or poorly lubricated internals in the gearbox. Or if the lever is bent/breaking.

I took the gearbox apart, cleaned everything, and put it back together, and it continues to do the same thing, but this time, it doesn't even have semi-auto capability. Everything looks like it is in good condition still. When I take it apart to put in a new air seal, I can take pictures of all the gearbox parts + the selector switch, if that will help any.

~Brian

[AxisOfOil]

Pictures would help.

Pictures that would help diagnose the problem:
1. Left side of the gearbox shell on the outside, where the selector lever is.
2. Inside the left side of the gearbox with the gears and tappet plate removed (pic of the cutoff lever)
3. Close-up of your trigger (top part that goes inside the gearbox).
4. Close-up of your trigger contacts (really just the front half of the gearbox, left side again.)

Other things that can help:
1. Manuscript of the curse applied to the gun (verbatim, including any ingredients, charms, or sacrifices used)
2. Magic
3. Hopes and dreams from 17 children. Crushed or chopped finely.