05 YZ450f - White Goo?

My good friend recently purchased an 2005 YZ450f. After the 2nd-3rd ride he noticed that there was some white ooozy gooey stuff leaking out of the rubber hose that I believe comes out of the head? It is the big black rubber hose that is by the gear shifter on the left side of the bike. The best way to describe the liquid is like (pardon me) snot. It drips out after the bike has been ran and is off. I would say there is about a half dollar size puddle under the bike after the last two rides. :cry:


what you are seeing is water mixed with oil. The hose is the breather hose that comes from the top of the head. Water can get in the hose from condensation and/or from riding environment. It mixes with oil residue and forms the sludge.

Take the tank off and pull the hose loose where it goes into the top of the head. You should fine that it is clear of any white goo here....just oily. If it is full of goo, then you have problems.

Thanks Wyatt. I will have him pull the hose tonight and we will see whats there. What kind of problems are we talking about if there is goo there?

I have been out on my 04 YZ450 a couple time on the ice. Mine is doing the same thing. It's normal, or at least all the YZ's I race with do the same thing. I got nervous too :cry:

Weird, I have an 04 YZ450f and have not seen anything like that stuff. I've never been in conditions that were below say 40 degrees Faranheit either.

A blown head gasket or similar problem that could allow water to enter the oiling system could cause sludge build up throughout the engine. I highly doubt this is the case here. Probably just condensation in the hose and maybe the bike was a little over filled with oil, and ......presto....you have sludge.

Its normal, my bike does it from time to time. Its really sporatic, sometimes it does it and sometimes it doenst do it for a long time.

The bike has had moisture/water sucked up into the breather hose - drain the oil..........

I agree with draining the oil as soon as you can. Put in new oil and filter and run it. Closley monitor the bike, if it is still happens or even gets worse you have a blown head gasket or possibley a split case somewhere. Do this and let us know. :cry:

Guys, its normal for some of us. I had no water in the oil and it happened over a year ago, the bike still runs how it did.

Guys, its normal for some of us. I had no water in the oil and it happened over a year ago, the bike still runs how it did.

Understand they all leak a little, that is normal. But it is oil that is dark in color that comes out of the breather tube - water will make it cloudy/grey - if you ride in woods/creeks be very careful to never stop while the bike is running or start the bike in water with the breather tube submerged in water/creek - it will suck up water into the engine as I found out the hardway on my WR426. They will leak a lot more if overfilled with oil also. I know several riders that reroute this tube so that moisture and water can not be sucked up into the tube. On my WR426 I had to change the oil several times before it stopped from leaking grey matter. :cry:

My bike has about 15 hours on it now. I rode it in 35 degree weather yesterday and got the same white goo/froth coming from the breather. I checked my valves today and there is none under the valve cover. The hot air coming out the breather hose is condensing the moisture in the the cold air and mixing it with the oil on the inside of the tube. The eingine vibration aids in whipping it into a white goo/froth. No worries.

Thats weird ive never seen that outta my bike at all. I have had mine for like a year and a half and it doesnt leak anything. HMM man this site scares me. LOL i always hear people having problems with there bikes im just waiting for something to happen to mine.

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