Norge airbox enquiry.

[Huzo]

Can anyone tell me what the foam cushioning stuff inside the lid is for ? After 19 years, mine has started to disintegrate so I’ve removed it.
I replaced the plugs at the 20,000 k interval and noticed an unusual sooty deposit on them that coincides with the destruction of the foam.
I wonder if it’s been ingested and burnt onto the plugs ?
Anyway, the foam has gone and she has new plugs…! 

[John A]

I believe it’s for noise reduction. That’s also why they put snorkels on the air box. Open intakes can be almost as loud as the exhaust sometimes.

[Huzo]

I believe it’s for noise reduction. That’s also why they put snorkels on the air box. Open intakes can be almost as loud as the exhaust sometimes.

Oh, ok.
Thanks John.

[Vagrant]

Just for noise for sure.

[guzzisteve]

There is no foam on the inside of airbox. It is on the underside of tank & the outside of the air filter lid. I have cleaned out more than a few from sucking in the foam. If it is inside it got sucked in when dry rot happens. It crumbles & falls off. If you don't check your airbox at all, I would start.
Aprillia uses a different item, use it to replace it under tank. The foam will cover your air filter BUT NOT GO THROUGH iT unless you have a crappy seal. You could use a GTM lid rim to hold filter so you can see in airbox anytime tank is lifted.
I don't think you are burning foam unless you run no air filter.

[Huzo]

There is no foam on the inside of airbox. It is on the underside of tank & the outside of the air filter lid. I have cleaned out more than a few from sucking in the foam. If it is inside it got sucked in when dry rot happens. It crumbles & falls off. If you don't check your airbox at all, I would start.
Aprillia uses a different item, use it to replace it under tank. The foam will cover your air filter BUT NOT GO THROUGH iT unless you have a crappy seal. You could use a GTM lid rim to hold filter so you can see in airbox anytime tank is lifted.
I don't think you are burning foam unless you run no air filter.

Yeah that makes sense, I have been in there dozens of times, but I mis described it.
Thank you.
Anyway, I have removed the foam.

[guzzisteve]

Most of the foam is gone on them now, some went in where the snorkel was. If you have never looked in your airbox on a Breva, Norge, Sport chances are it's full of dry crumbly foam. Especially if you have run-ability issues. Aprillia uses a foil type of material. An engineers bright idea, for sure.

[Huzo]

Most of the foam is gone on them now, some went in where the snorkel was. If you have never looked in your airbox on a Breva, Norge, Sport chances are it's full of dry crumbly foam. Especially if you have run-ability issues. Aprillia uses a foil type of material. An engineers bright idea, for sure.

Ah yes I have, I clean inside it at each service to remove oil mist condensation.

[PJPR01]

My foam crumbled and dried up years ago in the Texas heat.  I replaced the tank foam with a nice gold liner all under the tank for heat shield purposes as in extremely hot summer rides (north of 105F with heat indices above 115F), sometimes I'd get a bit of vapor lock, and have to vent the tank cap.

The gold shield even though invisible to others looks beautiful to me and far better than the crumbly foam, which could be ingested into the airbox.

:)