Holes in air boxes

[gimmeamidget]

Many years ago when I was a kid we drilled holes in the air boxes thinking it gave us more power. Nowadays I search for air boxes to put back to stock and they all seem to have missing lids or are full of holes. Can anyone tell me if there was any truth to the theory or were we just destroying parts?

[wrightracing]

It does create more air flow. The faster you can get air and fuel in and out of the motor, the more performance you get. Once you get more air in, you may lean out the carb and need to change the jetting richer. By adding a performance exhaust, you get the air out quicker. Also, bigger carburetors require more air, like my Trx250R upgrade on my CT310 motor to a 38mm CR500 carburetor. You do have to balance the amount of back pressure on a 2 stroke motor. If you take away to much of the back pressure, you loose the low end torque.

David...