BSE J1 250cc air cooled valve clearances

Hi guys, please can anyone tell me what the valve clearances should be on my 2015 BSE J1 250cc air cooled Mx bike as it never came with an owner's manual, also what make is the engine? And just one final question, where can I get a replacement air filter for it as the supplier here in the United Kingdom told me that they can't get me one!!!!! Many thanks for any replys. Steve.
PS. I have tried emailing BSE a few times but never get anything back.

These OHC 223 is based from JDM MD33E family http://blog.inmycab.com/xr200rmatome/761/ CRF230 (ME09E) is the most similar in western country...
In/ex: .1mm http://sawmee.jugem.jp/?eid=187
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What's the shape of that filter?
If it's like http://www.chinariders.net/showthread.php?t=16720 which = XR125L