engine oil on chain and rim after top speed

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.

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:

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.

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.

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).

Your welcome. Enjoy that new YZ!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now