Weird Flapping noises.

[Man]

So far now, riding for a few months now I'm experiencing some weird flapping noises. Usually it only happens in the first 10 min of riding, if i rev or downshift and rev match I hear the valves or something flapping. When I lightly reved today it just made a huge pop but the bikes was running normal. Only has 5000 miles. Usually after about 10 minutes of riding it stops and everything's normal. Anyone have any idea what it might be.

 

[Superzoom]

I wonder if it could be the chain being loaded and unloaded, and flapping a bit because of chain slack. The chain certainly makes a lot of noise.

 

[Man]

Hmmm i dont think that's it, i looked at the chain side and it seems fine, I pretty sure the noises are comming underneath the gas tank.

 

[Slick]

Air filter? Air Box ducting?

 

[Man]

I dont know, actually today when I started the bike it actually stopped. I think its if I downshift while the bike hasn't fully warmed up ( after reaching op temp and riding for 5 min). I didn't go to high RPMS and it seem to not happen. LOL