Valve cover vent tube relocation on a WR426 - again

6 replies to this topic
  • bfly

Posted July 31, 2004 - 06:14 AM


I was just wondering what TT members think about relocating the valve cover vent tube to the drain on the air box using a "T" fitting. Using the "T" you can hook the vent tube to the air box drain then attach the clear vent tube on the "T" pointing down at the chain. This would create a primative oil separator for the vent tube before the air box and allow the oil to drain on to the chain. Other than filling the air box with water and thus the vent tube what are the possible problems with this design?

  • bfly

Posted August 02, 2004 - 07:19 AM


Just a quick update. The oil separation effect seems to work quite well. My thought now is to replace the clear tube with a drain from an XR600r and use a "Y" instead of a "T" to allow the tubing to come over the top and get the drain further away from the chain.

  • gloft

Posted August 02, 2004 - 10:43 AM


I actually drilled a hole in the bottom corner of the air box and inserted a T-fitting then sealed it with silicone. It does as you say and allows any excess oil to drip on the chain but now that I've lived with it for a while I would not go with this setup as it seems to allow water in the airbox at times. I now think the best way is to T the vent hose at or near the top of the cylinder head and run a short piece of hose to the frame under the tank leaving the other piece in its original position. If you stall in water it will draw from the hose under the tank since air is lighter than water :thumbsup:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • bfly

Posted August 02, 2004 - 12:13 PM


I read posts about drilling a hole in the airbox but the 426's airbox is a little different than the 450. I figured the drain was as good a place as drilling a new hole as long as you "T"ed a one way drain in as well.

Did you use a one-way drain ala the XR600 or did you just have the "T" open and pointed at the chain. I really don't think you will have any problem with extra water getting in the airbox if you put a one-way drain on the "T".

  • gloft

Posted August 02, 2004 - 02:09 PM


I just used a one way T. I'm still not sure how water can enter unless bike is staled and water is up past the bottom of the air box :thumbsup: . Good idea on the one way valve. Any idea who sells those?

  • bfly

Posted August 02, 2004 - 03:33 PM


About the fourth post down in this thread has a link to a picture of a one-way drain for a Honda XR600r.

Airbox Drain

The picture has the part number as well (17358-HAO-680).

  • yz426onNOS

Posted August 02, 2004 - 08:41 PM


You could do it like this. This is what I did.

Posted Image


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.