Airbox & oil

[sprinter900]

Should the air box have a film of something that seems like sticky oil in it? on the filter aswell. I suspect not, what I beleive has happened is the drain hose has cracked near the bottom and has been sucking up junk from down near the chain/mainstand area. Could someone confirm for me please?

If this should be clean as I would expect it may be the reason it smells like its running rich.

Not sure about the airbox, but I believe the filter element is of the oiled foam variety. Filter oil is particularly sticky, viscous, nasty stuff. I put oiled foam pod filters on the KZ400 I rebuilt recently; I was shocked at how sticky the filter oil was.

Cheers,
-Kit

[BadMiker]

Doesnt sound right. I think the drain hose is supposed to have a one-way valve on it. If the hose had been sucking stuff up I'd expect to find a lot of dust/grit in the airbox. When I first got into mine there was enough rubbish to plant a palm tree and call it a beach. The filter (original) was coated in what looked like treacle too; from other posts, the airbox does seem prone to sucking up the worlds detritus.

Clean it out, replace the filter and carry on! While you're in there I'd strip the carbs and check that there's nothing nasty in there too.

[zippythehog]

I recently replaced my airbox with a factory unit ($$$$). After a tune up, I too have a bit of seepage that appears around the seams of the airbox halves. I believe this is normal. I installed a plug in the "road draft" line that exits from the bottom of the airbox. I believe that the offending oil is indeed from the filter element. When you are riding at a constant throttle position/gear, the airflow through the box is relatively constant. When you close the throttle (shift, slow down, run trailing throttle) the air is still flowing into the box upstream of the filter element. However, the throttle is not open, consequently, the airflow is momentarily mismatched. The airflow has to go somewhere. So, it goes out from the seams of the two halves of the box. As it does so, it blows the air filter oil out of the air filter. This is my best guess and I'm sticking to it (perhaps literally).
Zip

[sprinter900]

On 2006-05-17 05:21, BadMiker wrote:
Doesnt sound right. I think the drain hose is supposed to have a one-way valve on it. If the hose had been sucking stuff up I'd expect to find a lot of dust/grit in the airbox. When I first got into mine there was enough rubbish to plant a palm tree and call it a beach. The filter (original) was coated in what looked like treacle too; from other posts, the airbox does seem prone to sucking up the worlds detritus.

Clean it out, replace the filter and carry on! While you're in there I'd strip the carbs and check that there's nothing nasty in there too.

Well there is a smattering of junk in there - kinda small rock garden rather than palm tree plantation :-D

thx for responses