engine oil on chain and rim after top speed

5 replies to this topic
  • rrliedt

Posted November 22, 2008 - 07:14 PM


I semi-recently upgrade to 09 yz450f from a 05 wr450f so this is my first “motocross” bike. So anyway, I had it topped it out today a couple of times with 85.7mph being the highest speed (measured by GPS) (purely stock too) (~6500' elevation). When I got back to the truck I noticed some oil had come out of the crankcase breather hose and oiled my chain and rear rim a bit. Has anybody else experienced this? Did I simply have the revs too high? I’m pretty sure it was not overfilled and I only tipped over once today for just a second or two on the right side of the bike so I doubt it was because of the prior tip over, but maybe it was.

As far as every thing else goes – it’s a totally awesome bike!

Oh and sorry if this a old/dumb subject. I briefly searched and didn't find anything.

  • 642MX

Posted November 22, 2008 - 07:23 PM


Its completely normal to see some blow out when you run them hard. Don't worry about.

Hell of a way to break an 09 in.....lol. :bonk:

  • rrliedt

Posted November 22, 2008 - 07:28 PM


Thanks! I figured it was normal. I probably have done the same thing with my WR numberous times, but that vent hose routed back into the airbox, so it would be much less obvious on that.

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  • 642MX

Posted November 22, 2008 - 07:31 PM


Yeah, your WR just re-oiled the air filter instead of blowing it out. You can re-route the blow by tube like your WR. Lots of woods guys do it in order to keep water from getting sucked back in.

  • rrliedt

Posted November 22, 2008 - 07:39 PM


Thanks for the tip. I wouldn't have thought of that. I still plan on keeping the WR for the woods/water/hard-on-bike stuff. The YZ's for the desert rides (current plan).

  • 642MX

Posted November 22, 2008 - 07:57 PM


Your welcome. Enjoy that new YZ!

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