It'd help if we knew which AKM model it is, and who imported or built it. Something along the lines of Century Arms WASR from Cugir Romania, Norinco MAK-90, Interarms Polish, etc...???? Might give us an idea if it's a kit build or a factory rifle.
And no, carbon and oil isn't going to fix your problem. Likely the recoil spring is bad, or your bolt or carrier has an issue, or the rear trunnion is sitting too far back, etc...
Neca eos omnes. Deus suos agnoscet