Help**2009 YZ450 Milky Oil**

Eh everyone. Picked up my new to me 09 yz450 yesterday. Love it so far and hope it works just as good as it looks. I have noticed that there is a white substance coming out of one of the breather hoses, the biggest one on the front sprocket side. It smells like oil and i do not know what would cause this. The guy who i bought it from said he had the same problem and told me just to change the oil in the bike. I dont want this bike to frig up on me this soon as im only mowing lawns for an income haha. Im taking it to the shop to get a new rear tire and get the valves checked this week. What do you guys think would cause this to happen? Thanks.

Have you changed the oil or checked it. There's a check stick in front of the cylinder. I had a buddy that-happened to but he never ever changed his oil so once he flushed it out and regulary changed the oil it didn't happen anymore

I've got a 09 YZ and my oil isn't milky. I would try changing the oil first. Is the o-ring still on the dipstick and oil fillcap? Seems like moisture is getting in there somehow. Unless the previous owner took it in deep water perhaps??

I checked the oil level today and it was fine, no discolour to it or nothing. Im going to do an oil change later this week. I dont know if he did or not, buddy barely drive the bike, has close to 30 hours on it. Is this "milky oil" a serious issue if you leave it for long enough ?

Is this "milky oil" a serious issue if you leave it for long enough ?

Yes. I would watch the coolant level and see if any is disappearing. The previous owner may have gotten it too hot and popped the head gasket or warped the head which may be causing the engine to ingest coolant. You could get a block test from a local parts store which tests for combustion gasses in the coolant. Very quick and easy.

How would you check the coolant level on this bike ? I've never had a yammy before and just coming off a honda.

How would you check the coolant level on this bike ? I've never had a yammy before and just coming off a honda.

Just remove the radiator cap when the bike is cold. Should be to the top of the core inside (a little below the neck).

there can be condensation in the breather line that will turn the oil a milky color, just do an oil change and you will be good to go.

The oil from the breather hose will mix with dust and condensation and turn white. Its no big deal

oil can go bad very easy on a yz450f just change the oil and check how much comes out and ask the shop to diagnose oil and see what the outcomes is

The oil from the breather hose will mix with dust and condensation and turn white. Its no big deal

What he said. Don't sweat it. It is common especially if the oil is slightly overfilled. :ride:

Okay, checked the coolant level and it is a bit low. I have some Genuine Honda coolant i got with my crf250x a few years ago and I've never touched it before. How much should I put in ? And how do I put it in, with the bike running or shut off(cold).

you fill up the radiator till its full from the top by opening the cap

The coolant level should stabilize at a point just above the tubes in the core. Filling it to the top as suggested will only result in the bike pushing some coolant out as it heats up. When it contracts it will fall back to the point I just described.

What he said. Don't sweat it. It is common especially if the oil is slightly overfilled. :lol:

Yup, condensation in the breather not a problem :ride:

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