How do I motivate 11 year old Asian boys?

I teach English 11 year old boys in a large private school in Thailand. Parents send their kids here partly for the English program. The lads don't seem to know this! Or have much idea of how fluency in spoken and written English can enhance their lives. The local culture appears to value noise and chaos, and this penetrates the classroom. It's possible to gain the boys' attention by giving them a project. Solo projects require moving desks apart. Skill levels vary so greatly some students finish before others have written a single word. The fast ones respond well to extra work, but the slow ones usually give up after 5 minutes and move around talking. Group and paired projects quickly deteriorate into rabble. Instructions like No Talking and Sit Down are good for about 5 seconds. Teachers more experienced than I face similar scenes every day. Most Thai teachers have sharp tongues and use sticks, weapons not available to foreigners who don't speak Thai.