PitPro SX 250 engine rattle (valve chatter?)

[jazzyman9182]

Hey guys i need some help figuring out a problem with my bike. I have linked a video showing these noises. It has done this since we got the bike and it hasn't been ridden for a while but its getting really annoying and it doesn't sound right. I think it may be valve chatter, but i don't know much about engines and how to fix it. Just looking to see if anyone can offer advice on what i could do, otherwise ill just have to put up with it.

Heres the link:
PitPro sx 250 engine (valve?) rattle - YouTube

Thanks in advance
- Jarrod