I am having a problem with my Romanian SKS. The bolt does not always come all the way back. Sometimes it doesn't lock back on the last round and sometimes it doesn't fully eject the spent round. A search revealed that many have had this problem with the gas valve on the yugo models with the grenade launcher valve. The Romanian does not have this. I have throughly cleaned the gas system and checked the chamber for smoothness and all looks good. The whole gun including the inards looks like new. HELP!