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Tech Tip: Airbox Door Seal Failing?

Updated: Dec 23, 2020

Not the first thing you think about but check it next time you do the air filter, it might be in bad shape if your bike is a few years old.

DR650 airbox door and a breaking down foam seal

The issue

The door seal is made of a soft foam that doesn't age well. It could be allowing water to get in when going through water crossings for example.

When you clean the air filter it's nice to also thoroughly clean the inside of the airbox and the door. I tried to remove the seal strip of the door but then realized the foam was breaking in pieces and was completely flat as shown in the picture above.

If you never take it off the groove, you might not notice it but might be compromised and could allow water to get in.

The solution

Make a new seal with a better material!

Instead of using this type of not so durable foam for sealing material, you can cut a new strip into a more rubbery type of material like automotive weather stripping or any other soft rubber material than you may find.

  1. Remove the door and take the foam strip of the groove

  2. Check if still elastic and holding together, if not, it needs replacing

  3. Cut a strip about 4mm wide your new sealing material

  4. Install the new seal in the groove

  5. Screw the door back on

The picture below shows an example of a really nice rubber compound still soft enough to compress well but way more durable. Here I use only the flat portion of it.

Bonus is the tape in the back allowing to glue it in the groove.

Automotive door seal and cut 2/8" strip out of it

NOTE: Applying your new seal with a fine flat blade screwdriver helps a lot.

You can also pull lightly on the strip to make thinner as you push it in. This will make it easier.

Also when you are about to close the loop, cut a little longer and compressed the end in. If you don't, it could retract/move over time leaving you with a gap and thus no seal.

New seal in place and door ready to go back on!

You are now better prepared to ford the deepest rivers with the assurance the water will only get in from the top!

Or if you use a high-pressure jet to clean the bike, water will not get by the door and in the airbox.


4 Yorum

Yes, the stripping on my airbox cover was toast when I got my bike. I found a piece of window screen spline ...the round, soft-plastic strip used to hold the screen in screen windows and doors perfectly in the slot. The spline has just the right amount of "snug" to stay put in the channel of the door, the right amount of "give" to act as a decent seal and is a lot more robust than any foam.

Actually, if you think about it, you *really* don't need to have the door totally sealed (as in air tight) because ...there's a big honking filter inside the box to filter the nasties. And there's a hole (of varying size) on…

BP team
BP team
09 Mar 2023
Şu kişiye cevap veriliyor:

Great tip ! Thank you! That is a perfect replacement for this.

You are right, the seal doesn't need to be perfect from the air point of view since there is a big hole on top, and the filter is here to filter.

But for me it was more about sealing the box from water ingress when you do deep water crossings or drop your bike in water. It's important to have the door sealed so that you know water (and air subsequently) can only come in the air box from the top, through the opening for it.

I also glued a stainless steel mesh screen on the opening to block large particles and rodents! 😄


Orlando Vazquez
Orlando Vazquez
04 Oca 2023

Be advised: I'm a very silly person from the Internet, follow this advice at your own risk! Since it seems common-place for people to oil/grease gaskets and o-rings prior to installation, I have taken this a step further. When I clean my air-filter out, the last thing I do before I close'r up again is to apply grease along the sealing surface of the airbox door (cleaning up any excess of course). I like to think it helps trap any dust that might want to get sucked in via small any small gaps or imperfections.

BP team
BP team
04 Oca 2023
Şu kişiye cevap veriliyor:

Good tip! Same idea as when you grease the contact surface of the air filter.

Just don't do too much to avoid the mess of grease and dirt on the outskirt of the rim.😉