My bike doesn't have any airbox. It has been cut by a former owner

Here is one picture : http://img513.imageshack.us/i/29octobre2009008.jpg/" onclick="window.open(this.href);return false;
As I bought it as a track bike (and I use it as such), I suppose he wanted to increase the airflow

Have you ever seen this on an nc30 for the track? Is it dangerous?
Can it damage the engine?
Without the tank, the blend "gas - air" was poor (or rich, don't remember

Is the ratio gonna be the same with the tank on the bike or not?
What would you do? As you know much better the nc30 than us (the french

I think I'll have to buy a complete airbox, no?
Many thanks mates
