NSR Air Box

[Skinned]

I've got a JC20 NSR125R which I've not had long, I set about servicing it when i got it. Managed to get the bike running very well, then yesterday fitted my brand new all singing all dancing genuine honda air filter.
Bike started running like crap, would bog out at 5-6000 rpm and generally felt lifeless.
Originally it had one of those cheap ebay cone filters on when i bought it which I removed and fitted the standard box.
When I bought the bike, the carb had all ready had the restrictor plate removed.
So I have stripped the carb down again, cleaned and rebuilt, cleaned everything up the bike still would bog down.
In a fit of madness today I took the spare airbox I had and drilled 8 holes in the top to try and increase the airflow, and bloody hell its done the trick, but now I'm wondering about the long term effects of my madness, I have another unharmed box I can put back in and just looking for some advice on it really.
The carb looks standard and I've drained the excess oil out of the filter before initially fitting it.

[skatefreak]

Could be the jets in the carb...
I couldnt advise you any more specifically but i would say it sounds like its running rich when you restrict the airflow (to much fuel).

I dont suppose twddling any needles will help really, but i'm sure someone will tune in with some advice in which way to go...

If you have the carb out have a look and let us know what jets are in there

Best regards

-Jvr