where does the vent hose on my valve cover connect to?

5 replies to this topic
  • cammeddr-z

Posted June 12, 2009 - 08:27 PM


i got an '04 wr450 that was a bit of a basket-case and i can't quite figure out where the larger (abour 1/2" diameter) vent hose on the valve cove connects to. on other bikes i have had it connects to the air boot, or air box, but i see no such provision to connect it to

where does it go? :thumbsup:

  • JSanfilippo

Posted June 12, 2009 - 09:43 PM


It vents to the atmoshpere.

'05+ it vents to the airbox.


Posted June 13, 2009 - 05:41 AM


As mentioned it vent to the outside world. Actually there are two hoses attached to the valve cover. The large one is the vent and from the factory the hose is routed down along the front frame tube and dumps just in front of the shifter. The smaller one comes from the oil reservoir in the frame.

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  • Lcpl0331

Posted September 27, 2009 - 01:46 PM


Is it possible that on deceleration dirt/dust can get sucked up into the valve cover? On my last oil change I had the most dirt I've ever seen in my oil filter and the oil was like brown water. It was cooked. I can't figure out how that much crud got into the oil. I usually go 125-250 miles between oil changes but this time I went about 200. I use spectro semi synthetic 10/40. Any thoughts would be appreciated.


Posted September 28, 2009 - 05:52 AM


On my '08 I capped off where it plugs into the airbox and routed it up near the steering head and put a uni filter on it. Ideally, it should be routed up (so as to retain any oil that blows out) and then down (to prevent water from entering) and then capped with a filter. I don't ride in water, but still, the filter ends up pretty high near the top of the radiator.

  • Lcpl0331

Posted September 28, 2009 - 05:24 PM




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