Importance of sealing airbox?

[Guest]

Hello all,

I have seen numerous references on this forum regarding thorough sealing of the factory airbox - more thorough in fact than they came from the factory. I bought my '81 GS850G a few months ago with velocity stacks (17K miles), which I understand is a no-no with these engines, so I bought a good used airbox on Ebay along with a new filter. The rubber boots are in good shape, as are the seals at the ends of the airbox, but it seems as though some people on this site think that's not sufficient. So my question is: is it really necessary to seal them better than they were from the factory?

Any insight would be greatly appreciated. I want this bike to purr.

[Nessism]

So my question is: is it really necessary to seal them better than they were from the factory?

.

No need to go beyond the OEM level. Problem is that the airbox foam deteriorates with time; foam on the airbox end cap and on the filter cage. The rubber carb boots that attach to the head typically get hard and crack and the O-rings fail. The airbox boots typically shrink so that's something else to watch for. Bottom line is to bring the system back to OEM level and you are fine.

[Guest]

Thanks for that info Ed. That's what I figured. So I have all new intake manifolds, the airbox boots are still nice and pliable, the foam air filter is new, and I have brand new chrome end caps. That oughta do it, right?

[wymple]

If the airbox isn't sealed well, crosswinds will play hell with your carbs.

[Joe Garfield]

If the airbox isn't sealed well, crosswinds will play hell with your carbs.

Is that specifically referencing the end caps?

[Dogma]

Is that specifically referencing the end caps?

End caps, carb vent tubes position, and probably the snorkel too. You don't want any opening to the intake exposed to the wind.

[Guest]

End caps, carb vent tubes position, and probably the snorkel too. You don't want any opening to the intake exposed to the wind.

Motorcycles operate in wind (as they move down the road). I would think that the engineers would have considered that as they were developing the intake-sealing methods.

[Dogma]

Motorcycles operate in wind (as they move down the road). I would think that the engineers would have considered that as they were developing the intake-sealing methods.

Right. So, for a stock intake, make sure all the stock sealing stuff is sealed. That will put all the openings (snorkel intake and carb bowl vents) in the space between the side covers and under the seat. Out of the wind.

[Guest]

So one last detail about sealing the airbox: as I mentioned, I bought my airbox used on Ebay, and all is well except that there is a gap between the top of the air cleaner element and the ceiling of the airbox; it is about 1/8", maybe a little less. I think I've seen traces of old weather stripping in there - as though that gap used to be sealed. So given that everything else it tight, is it really necessary to seal that gap?

[bwringer]

So one last detail about sealing the airbox: as I mentioned, I bought my airbox used on Ebay, and all is well except that there is a gap between the top of the air cleaner element and the ceiling of the airbox; it is about 1/8", maybe a little less. I think I've seen traces of old weather stripping in there - as though that gap used to be sealed. So given that everything else it tight, is it really necessary to seal that gap?

Abso-freaking-lutely. Yes.

It is important to the correct airflow, plus you also don't want to suck in dirty air.

I generally clean the metal air filter cage thoroughly (remove the foam filter element so you don't damage it with solvent), then apply weatherstripping to the top of the cage (it takes a bit of craftsmanship at the corners). Then apply a thin coat of grease to the foam so it'll slide into place inside the clips in the airbox.

[Guest]

Abso-freaking-lutely. Yes.

It is important to the correct airflow, plus you also don't want to suck in dirty air.

I generally clean the metal air filter cage thoroughly (remove the foam filter element so you don't damage it with solvent), then apply weatherstripping to the top of the cage (it takes a bit of craftsmanship at the corners). Then apply a thin coat of grease to the foam so it'll slide into place inside the clips in the airbox.

Alrighty then! Looks like that's my project for tonight when I get home from work. That should go well with my newly-rebuilt carbs by Steve (GSWhisperer).