Cyma CM046 AK47 semi/auto problem - need advice!

[romandesign]

Great gun with blowback and real wood - but I got it with a problem. First it often (but not always) would not engage in auto mode, it would shoot semi in auto position. Nudging selector up and down again would usually fix it. Then it would stuck in auto mode (in safety would not engage and it would always shoot auto). I removed the selector lever and it seems that little cylindrical part was not fit snugly with the lever and it would become loose. I filed the hole in the lever a bit until it sits snugly, and it fixed a "stuck" problem. Now it seems to move correctly, safety engages OK, but I'm back to the original problem, only worse: it almost always shoots semi in both semi and auto positions. Very occasionally after moving lever several times it would shoot auto, but after going to safety and back to auto it shoots single again. Safety engages OK now, but sometimes in semi and auto position I feel that trigger movement is not smooth, as if it catches on something, like safety, but not hard enough to lock it.

Does anyone know what could be the problem and how to fix it? I'm not even sure how to disassemble it. But I'm generally good with mechanics so should be able to figure it out. Is semi/auto a fully mechanical switching, or is there an electrical contact that triggers auto that maybe doesn't work properly?

All advice appreciated!

[Comeau-SCS]

If you are lucky it might be just the external selector that is not fitted correctly on the gearbox selector plate. It could also be the selector plate on the gearbox that cause the problem.
It's VERY hard to know without pictures but in all cases these are very unexpensive parts if they are broken.