Airbox with OEM Filter: Fitting Issues

[Mendizale]

I'm having a hell of a time securing the wing nuts of the airbox after installing a new OEM air filter--it's almost as if the filter is too tall. I can get the two forward nuts, but the aft ones (that go through the filter) don't come close.

Any tips?

[jeffro1954]

welcome to my world. Mine is on, but not all 4 are screwed in. Need a video showing how it's done.

[Mendizale]

If I'm not mistaken (50-50 chance), if they're not all screwed in, then there's a crack all around the filter box for unfiltered air to get in to the carburetors and combustion chambers. My understanding is that this is bad. Anybody have ideas to help us out of this fix?

[Tropic-al]

Check the old filter.

I'm having a hell of a time securing the wing nuts of the airbox after installing a new OEM air filter--it's almost as if the filter is too tall. I can get the two forward nuts, but the aft ones (that go through the filter) don't come close.
Any tips?

Make sure the old filter's top foam surface was not left stuck to the top of the box. Mine had almost disintegrated from a gas leak and when I took it off I did not notice the top piece being left inside.
After a few tries I finally figured what was wrong. Took piece out and everything went in perfectly.
Hope this is your problem as well.

[jeffro1954]

mine did fit better when I took out the old gasket, but you may have hit on something, maybe I didn't get it all out.

[Mendizale]

Just checked, and that's not the problem. If I had a second set of hands, or some clamps, maybe I could get it...

[James England]

You're using a pattern filter and not OEM, yes? I put one in mine and had exactly the same problem. I think some of the pattern ones are a bit too tall. I actually dented the side of mine and crushed it a bit before putting it in. Then tightened the wing nuts firmly and it then crushed the filter a little bit more as the cover compressed on. It's fine and filters correctly and seals etc....

[WMarshy]

Just go buy a K&N and you will never have to buy another filter!

[natemoen]

I had a K&N filter that had shrunk a little bit over time and it was not sitting all the way down on the bottom half of the airbox, could be something similar.

[Barnfresh]

I agree with James - my paper filter from Gfix is about 1/4'' too tall. I put mine in a vice between 2 pieces of wood - squished it down and bowed it out, being careful not to rip the paper loose top or bottom, which was enough for the threads to catch.

[redbone]

speaking of those airbox studs and nuts, does anyone have a couple extra laying around?? a couple of mine have fallen out.
tx
redbone

[James England]

speaking of those airbox studs and nuts, does anyone have a couple extra laying around?? a couple of mine have fallen out.
tx
redbone

If you don't find any, use a long bolt with a wingnut all the way down, then lock it tightly in place with a nut and put a washer on top to make contact with the airbox

[Mendizale]

Well, I was able to come up with a fix, but before reading your suggestions. Lacking a vise, I picked a horizontal line of honeycomb in the middle (vertically) of the filter, and snipped every other joint. I then took a pair of needle-nosed pliers, and bent the remaining joints outward a little bit, which allowed me to compress the filter between two pieces of clean wood. Seems to have done the trick. I'm going to try to squeeze the airbox a little bit more today to close the hairline gap that remains (in this case, hairline= ~1/16 in).

Thanks everybody!

[James England]

Well, I was able to come up with a fix, but before reading your suggestions. Lacking a vise, I picked a horizontal line of honeycomb in the middle (vertically) of the filter, and snipped every other joint. I then took a pair of needle-nosed pliers, and bent the remaining joints outward a little bit, which allowed me to compress the filter between two pieces of clean wood. Seems to have done the trick. I'm going to try to squeeze the airbox a little bit more today to close the hairline gap that remains (in this case, hairline= ~1/16 in).

Thanks everybody!

The airbox will always have a little hairline at the joint. It doesn't matter. The carbs suck air from inside the filter. That gap isn't letting unfiltered air into the carbs. You may have read here how some people drill holes underneath the airbox, to let more air in. That hairline is normal.

[CatatonicBug]

The airbox will always have a little hairline at the joint. It doesn't matter. The carbs suck air from inside the filter. That gap isn't letting unfiltered air into the carbs. You may have read here how some people drill holes underneath the airbox, to let more air in. That hairline is normal.

I have to disagree with you there James. There is a rubber gasket that is supposed to seal that "hairline" when the 4 bolts are tight. When folks drill the airbox, it's only the area INSIDE the circle of the air filter. Air usually comes in through the snorkel, through the filter, then into the main airbox cavity, then into the carbs. If the seam between the 2 halves of the airbox is leaking, unfiltered air is getting into the carbs. Now, how imperative that is, I don't know, but it would be unfiltered air.