Bonneville America Forums Forums Technical Forums Performance Mods Airbox drilling with K&N filter

Anyone drilled out the bottom of the airbox whilst using a K&N air filter.? Its just that I noticed on mine the K&N sits on top of some tabs in the bottom of the airbox. These are positioned so the filter will not seat on the base and therefore leave an unfiltered gap around the base.I was thinking of using some silicone type sealant to fill the gap once I drill the holes in the base of the airbox and filter.
Wondering if anyone else has done this or similar...I noticed most people that have done this mod are using the Uni filter.

Cant you drill a hole in the filter first that is "inside" the circumference of the tabs and then place it in the airbox and trace the outline of that hole in the bottom of the airbox? Thereby getting an exact fit/seal after you drill the bottom.

I think thats what is done with the UNI.

Are you sure its sitting on and not between the tabs? The stock one sits flat on the bottom and the tabs keep it from moving around.

This one sits on the tabs..you can see the little indendts from the tabs on the base of the filter. Its about half and half. I you were able to sit it right down on the base of the airbox (which you can't) the top would then be a loose fit and unfiltered air could get in that way. I will try some self adhesive foam strip around the base and cut the bits out where the tabs are.
Thanks for the reply

That is what I have done but as I mentioned the filter will not go over the tabs even when you have cut the base out.I think the K&N is different to the UNI.

what i did was put filter material from an electrical cabinet. It is 1/4" thick and cut to fit the bottom of the air box. air and dust did leak through even before i did this mod which was evident by the dust inside of the box. The filter material worked out great though. I got it from a local hardware store.
Jack

You guys should check out the Tech Vault under Intake/Carbs.

2k6 speedmaster, dealer had already jetted bike and put on shorty straight pipes, unfortunately i don't know the jets they installed. Looking to do an airbox mod, reading alot about ghetto freaks, drilling, etc.. here. Has anyone documented the procedure? Also are the aftermarket petcocks worth it for jetted bikes? How bout a vaccuum controlled pet ******? Any advice is greatly appreciated. Thanks

you shouldnt need an aftermarket petcock for only re jetting and K&Ns. but they sure are pretty

jetting, straight pipes existing, next airbox work. Bike does run flawless as is (unless I don't know what I'm missing : - ) Is it possible to kill two birds with one stone and get an automatic performance petcock?

It makes more sense to enlarge the opening at the top of the stock airbox/filter retainer using a file, rasp or knife.

My K&N seals up snugly, you may have something out of whack.

My Rocket 3 sucks a ****** of a lot more air than my Speedy and the R3 stock airbox (with the same top opening as a stock Speedy) lets in plenty of air for TOR's, a remap and a K&N filter. The R3 smokes about anything out there 0-60 MPH if you do not mind replacing he rear tire every 5,000 miles.

I had a K&N filter in my 03 TA and it was a direct replacement.... fit flush with the bottom of the airbox just like the stock Triumph filter???

I drilled both the filter and the airbox at the same time with an 1 1/4" hole saw, so I could put a button plug in the airbox hole if I wasn't happy with the results.

I wasn't, and I did...