My airbox mod

[NightBiker07]

Got it done. I didnt have to use a piece of plate or lexan for this, I just cut the whole face out of the 98 CR250 airbox, and ONLY cut the cage out of the CRF450 box to start. Then using a ROTOZIP, I carefully cut out the CRF box until just the edges of the CR face overlapped.

I only wound up with one small hole in the bottom front down by the exhaust that needed to be filled with silicone, when I was shaping the curve in the CR faceplate where the exhaust cutout was, I mis-marked it.

On the left side, there isnt much in the way of attachment, as in order to get the thing positioned in the box, I had to really get the new cage pushed to the left as far as the box would allow (the exhaust cutout in the stock airbox is HUGE).

But, it is sturdy, and pretty well sealed up. But that doesnt really matter anyways. As long as the metal cage is sealed to the boot, and the filter is sealed to the metal cage, no dirt is going into the motor.

[Gmbond]

Looks pretty sweet! Nicely done!

And you are totally right, as long as the boot is sealed to the flange and the filter is sealed to that then you are good. Air has to get into the airbox somehow, the front isnt ideal but it sounds like you got that sealed up okay.