Engine ZS177MM (nc250 4v)

Hi !

I am sorry for my english.

I have motorcycles with engine ZS177mm (nc250 4v). This engine have some china moto, sport bikes (cbr250r replica) and dirt, crf250r replica.

I have very big problem - can't find manual for this engine, and dont know valves clearances ...
In stock it has very low clearances, about 0.03mm both.

I was search all around internet, but nothing ...
Was contact with AsiaWing, thay say that for this motor normal is 0.06mm both In & Ex

I thinks that is very low .... I try to set 0.10 in & 0.15 ex - performance is very good, but i hear CIK CIK sound ....

This engine i think very popular in china, may be somebody can help to me for find this information?
I like to setup valves properly, for performance and sound was be good!

Thanks!
Very wait for any help, brothers!