This was/is a common problem with 2008 models. The crankcase breather chamber (which sits on the crankcase under the throttle body) didn't have enough baffling in it, so more oil mist than ideal passed through to the airbox and on to the drain tube. This is only a real problem on extended high speed runs.

The part was updated for 2009> and was available as a free "retro fit" at dealers for bike's under warranty, although wasn't an official recall - the customer had to request it. The only part available now is the updated one (11D-E5371-12) and it costs about �15. Fitting it will cure the problem completely.

I have had an '08 XTZ since new and have the same issue on long runs. I have never bothered to change the breather, partly because it had ran out of warranty when I found out about the issue, but mainly because it's a ball-ache to change the part even though it only cost peanuts, and I don't mind emptying the drain tube (which I have extended in length).

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