swisscheese for air box

[GNEPIG]

... hello again everyone, i have read about drilling out the air box all over this site but have not found any links on the subject on exactly what to do .. at first i had visions of air boxes looking like swiss cheese, but after thinking about it for a second i realized what was going on and knew people had to be talking about the space inside the air filter on the bottom half of the box
.. i have three questions.. how big do you make the holes?
.. how many holes do you drill?
.. and in what pattern should i make them?
any ideas would be helpful

gene

[skids]

Start with a few holes on each side and if you don't like the difference in performance, you can plug them off with short bolts.

[Pat Kelly]

The only place to drill hole to allow increased FILTERED airflow is in the center of the underside of the airbox.
Air flows in the snorkle under the seat to the inside of the airfilter. The engine draws the air from the inside to the outside of the filter. The debris gets caught on the inside of the filter, not the outside.
If I was to drill mine I would also epoxy a screen over the holes (on the outside of the airbox) to prevent 1/4" things from crawling/getting sucked inside (refer to the thread with the mummified rat in the airbox).

[skids]

That is true. I meant in the center area that is unfiltered intake air, and because it is a long area left to right, put a few holes on the left and a few holes on the right of the center line...

Originally posted by Pat Kelly
The only place to drill hole to allow increased FILTERED airflow is in the center

[GNEPIG]

ok, what if i just cut the hole bottom out between the mount screws on the inside of the filter?

[Dennyz]

Don't cut the entire section out. It will flex and let the filter come loose inside (stop filtering). I drilled 4 .75" hole in a staggered pattern.

[randy]

When I bought my 81SH, the PO had done that to the air box. I found it was very noisy at high RPMs, so I covered it. Couldn't notice any difference in performance.

[GNEPIG]

thanx men, before i read the last two posts i went and drilled two 1/2 inch holes in the bottom and ive noticed that the bike has lost some power/torque on the bottom end.. i guess ill be trying on some bigger jetting from here