125-200cc How to adjust power valve? SMS 125

Hi. I have question to to adjust it because i had problem with power valve and i moved this screw (attachment) and i dont know wchich position it should be? I dont want to fire up exhaust valve engine so could someone help me? Which position it should be? OR maybe motorbike will automatically set it? Need fast help, guys

isnt that a bolt instead of a screw? it looks like it just holds the cables in place on that circular arm, it doesnt set the position of the cables or the tension on them, that's done by the length of the cables themselves, do that bolt up just so it's tight, I'm sure it is only there to hold the mechanism together, not to change how it operates. The cables have tension screw things further down towards the cylinder to lengthen or shorten them