You can drill holes or add these Uni Air Box Filter Vents Blaster Warrior ATV Dirtbike | eBay or this EHS Racing Blaster Air Box Yamaha Airbox Outerwears | eBay
I've got a vented box but I don't like it because it lets water in.
If you've got the money and plan on building your motor a lot this is a pretty good option:
Yamaha Blaster Aluminum Air Box Airbox Intake CFM Performance | eBay
It requires a different filter
I have a CFM airbox and it still lets water in.
Well that makes spending $150 on one seem even less enticing. Maybe il try an outerwears lid and some baffling under the seat, I suppose I could just put a stock lid back on too.
any change in air filters may cause a change in breathing and jetting should be confirmed by a plug chop.
Going from stock to a uni filter can make a difference of 1 or 2 jet sizes depending on just how much and what oil is used to coat it.