200cc chinese quad won't start
 

Hi forum,

I have this 200cc Chinese ATV, that won't start.
I have thoroughly cleaned the carb - new oil - new sparkplug - new battery - new gas. When trying to start it sometimes makes a little sound/growl from the engine.

Any ideas here? Also, does anybody know what is under the hex bolt red circled.

https://cimg9.ibsrv.net/gimg/atvconn...ee29137e53.jpg
https://cimg1.ibsrv.net/gimg/atvconn...a7ce399ba1.jpg