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can't get a good seal on the airbox??

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I'm not sure what I'm doing wrong, all I know is I gotta fix it before I wreck my motor. Back when I had a kx-250, I had a hell of a time getting a seal. After riding in the sand I would pull the air filter and find small bits of sand inside the intake. I bought a new cage and new airfilter and it didn't seem to help.

I just bought myself a 08 xc 250 and the same thing is happening. I pulled the airfilter, cleaned it, oiled it up, greased the f-- out of the edges, and went for a ride. Pulled it afterwards and again, small bits of sand and dust in the intake and carb. What the hell am I doing wrong?? Should the intake be spotless?

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Are you pulling the seat to install the filter? Mine is a pita also, if not careful, the filter cage on mine will actually pull the air boot into the inlet really screwing mine up.

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Pull the seat when installing the air filter. Once the filter is on but before you pull the keeper over it, grab the cage through the filter and work it into airbox...you'll feel it snap into place. Does this make sense? Hard to explain.

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thanks, that makes a lot of sense. I wasn't pulling the seat, I assumed it was "tooless" and could just be swapped like that quickly. So how much harm did I do to my engine? I am thinking about a top end rebuild just for peace of mind. Do I need to flush out the bottom end as well?

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I always remove seat, but I dont see what the hassle is with locating the airfilter in the correct place????????? I mean the plastic insert that goes onto the foam filter can only go one way!!!!!

Just for a hint I always smear the edge of the filter that is in effect the sealing lip of the filter with gp type grease/ vaseline so when you put the filter on it compresses to the airbox to help create a seal. I did this with my XR4, 450 EXC and now my 250EXc for the past 5 years and very little has ever got in

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They are a pain. Practice puttin the cage in without the filter. You'll see how it pops in the boot.

Then you can install the filter and feel around the edge where it meets the boot and feel the gap. If its out of position you can feel a large gap between the cage and boot.

I had mine do that when I first bought it. I had rocks sucked into my air boot. No rebuild, 50 hours ago. They are tough.

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put on a disposable glove

use your finger goes around the filter/filter cage to make sure it seat in properly.

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put on a disposable glove

use your finger goes around the filter/filter cage to make sure it seat in properly.

In fact, put on a pair of disposable gloves and run your fingers all the way around the filter to make sure the cage/filter is in place. The only way to do this is with the seat off. I put BelRay waterproof grease all around the opening of the air box boot instead of putting it on the filter. This way I know I've got a good layer of grease where I want it.

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They are a pain. Practice puttin the cage in without the filter. You'll see how it pops in the boot.

Then you can install the filter and feel around the edge where it meets the boot and feel the gap. If its out of position you can feel a large gap between the cage and boot.

I had mine do that when I first bought it. I had rocks sucked into my air boot. No rebuild, 50 hours ago. They are tough.

good tip:thumbsup:

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One time a while back I had the bike torn apart for cleaning. Sub frame, airbox all in pieces. I took some time with clean stuff and easy access to play with the air filter frame and try to install from every angle possible. I found it was easiest to inert the back top corner first then press the bottom front into place. Now I can install with the seat on and check with my fingers to be sure it is sealed. I leave the gloves for my son;) Also cold temps will make things harder. A nice warm garage helps, if very cold put some heat on that airbox boot so it has a little give.

Joe........

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Joe, I have noticed the same thing as there is a flange on the top corner of mine to help seat and leverage the cage.

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Are the 2011's and newer different? I just did my 2011 XC and it seemed straight forward, but I'm starting to think I need to make sure some think clicked into place. I did the whole "running my fingers along the edge" thing to make sure the fitler was sealed.

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I never had issue with my 05, and have found that my 08 seems "in place" when it is NOT. without running my fingers around the cage, it is hard to tell. I think this is where many get into trouble, having engine issues.

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I am not sure on the 2011's but the 2007 SX models, 2008, & 2009m for sure are very different than the older design. They are a PITA but after you get used to them not so bad. I think KTM was going for a design that would ensure a snug fit. Too bad it is still a pain. The keu is the finger check around the edges. Run your fingers around and be sure it is sealed. If it is off you will feel it.

Joe.........

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these type of air filter box is unique.

also, its just everybody said. work the cage/filter on the box lip. the form of the cage, box`s lip and the air filter is one shape and all has to be align for that shape.

i usually take my right hand fingers and apply a tiny pressure on the center or the filter and with my left hand fingers, go around the edeges of the filter/cage to apply pressure around so they fit snugly.

i then hook up the locking arm temporarily at the inside side of the air box (notice i said at the inside side of the box but not yet lock on the hook).

and again, at this stage i work my self around the edges.

then i hook up the arm on the hook then do a last go around the edges of the lip.

carefull that yoiu only apply pressure OVER to where the filter is pinched on the cage. dont go in too far the center that you might pop the filter and make it "slide" out of place and thus create a window for dirt.

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I use one of those neoprene seals and it helps the filter fit tighter.

Does Moose make a filter with neoprene lips?

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The neoprene seal is a seperate item that sticks onto the airbox. I can't remember who makes it.

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