07/08 air boot and box

REVERUP

Gold Level Site Supporter
Is it just my bike or does the new design let in way to much water and crud into the air boot and box? It seems the air boot is just press fit into the box with out any sealant. Water also enters up toward where the rear fender is attached to the sub frame.
85 enduro miles of wet Washington single track and my air box was full of mud and the motor definitely drank its share of water. It never shut down, but I'm sure it took some hours of its life.

A enduro bike sent out of the factory like this, pathetic! As you can tell I'm not very happy with this lack of R and D of this new air box/boot design and the lack of any sealant used to ensure a good seal.

If you get a 2007 and up model, pay much attention to this area and seal it up like it should have come from the factory.

O.k. I'm done with my rant now and i still do really love my Gas Gas.:)

Roscoe
 
Roscoe,

You can seal the airboot to the box, and I've done it, but thats not actually most important when you think about it. The filter seals on the inside edge of the boot lip, pinched by the filter cage right angle. The airbox acts like a support for the airboot for the spring loaded retainer to push against. Look at the filter when you take it off, it should have a deep crease where it sealed ALL THE WAY AROUND. Grease the rim good on install and get your hands in there making sure the cage is forcing the filter rim into the boot, not just resting on the flat part. I know at first I thought it was a POS too, but I've had no issues with just a little care. The inside of my airboot is always clean and the filter rim always creased indicating a good seal. As far as water getting into the airbox, yes mine does it but no more than my older GGs.

If you really can't get past it, you can swap a pre '07 airboot/filter ring and use the pre '07 filters, you just have to modify/drill the airbox slightly to accept the older air boot.
 
Glenn, This is my take on it.

I think the main problem is the mud gets in too easily and fills up the bottom of the air box and then plugs up the little flapper drain hole.
Then as more water enters the box it fills up and even with a well greased and sealed filter, cause mine surely was, the motor pulls that dirty water that has built up to the bottom of the air filter through the filter cause it cant drain fast enough.
It was a very wet and muddy fast pace, but I've rode far worse on the older style air box and had way less crud in my air box when I was done. The old drain on the old air box is a better design IMO. I plan on modifying the drain on the new air box so this hopefully doesn't happen again. I think the main reason for my rant is I feel I shouldn't have to modify this it should be ready for the worst conditions.

Roscoe
 
Roscoe,

I have a little trick I've used on GGs since '00, but not on my '07. The older airbox just had a baffle in the bottom and let a lot of water in during deeper stream crossings. The bottom of my filter was always wet and dirty. I cut foam blocks to fit in the well over the baffle. This prevented water and mud from filling the box from the bottom in a short water crossing, and also allowed splash water to drain through. Give it a try. Also check that flapper to see if it really drains. Seems stiff, but I havn't had a problem yet. If you add the foam you can get rid of it.
 
Hey Glenn, Yep the flapper was too stiff so I added a little bit of heat and flexed it away from the box a few times to break it in. It still rests against the air box as designed, but feels much more flexible now.
Then I added some foam in the bottom of the box like you mentioned and stuffed some in the crevices by the rear fender and sub frame to help keep the mud and debris out. A bit of water in the air box don't bother me as long as it will drain out fast and not build up.
I still have a couple more months of pretty wet riding here to test it out and make sure it is the best it can be.

Roscoe
 
What about the access to the air filter on the 450 fsr ´07? I find it very hard to take it out unless taking the side panel off also with the seat because of the battery... Has anyone any advice on making it easier by making some quick release on the battery holder/bracket??
 
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