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Milky fluid coming from exhaust port

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I have a 2009 YZ 250 with about 35 hours on the top end. I recently took the expansion chamber off the bike after I had the bike running for about 5 minutes. I noticed some milky liquid on the cylinder head where the expansion chamber connects. I attached a picture. Any idea what it is? Water in the engine? Or is this normal?

attachment.php?attachmentid=385965&d=1320557872

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Looks kinda like coolant and oil... exactly what the tranny oil looks like when coolant leaks into the bottom end.

Yep. When my water pump seal went out, and coolant leaked into my tranny, this is exactly the same stuff that came out of my drain-plug.

Check your coolant level, see if it is being consumed during operation.

It is a bit concerning that this is coming out of your exhaust... if it is coolant: it could be getting into your exhaust via a cracked head, or more likely a leaky crank seal. Is there any chance you got water into your system somehow, cleaning maybe? Was there any white smoke (steam) coming out of your pipe when running?

Check your coolant level. And drain your trans fluid to see what it looks like.

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NVDESERTKID, it is quite likely I got water in my system. I do wash my bike with a pressure washer but I don't know how I would have gotten water into the engine. Yes, there was white smoke coming out of the pipe. The coolant level does not appear to have gone down. It has remained consistent.

Should I run my bike to work the water out? I would think there is probably a little in there that will work its way out. I will drain the trans oil but I don't think there is any water in there.

Thank you for the replies.

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How strong is your pressure washer? and do you blast the engine or the pipe-cylinder joint? I'd run your bike for 10-15 minutes and get it hot (get on the pipe and make some smoke!) and then check again. I doubt you'll see any, the pressure washer can get water in some weird places.

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Yep. When my water pump seal went out, and coolant leaked into my tranny, this is exactly the same stuff that came out of my drain-plug.

Check your coolant level, see if it is being consumed during operation.

It is a bit concerning that this is coming out of your exhaust... if it is coolant: it could be getting into your exhaust via a cracked head, or more likely a leaky crank seal. Is there any chance you got water into your system somehow, cleaning maybe? Was there any white smoke (steam) coming out of your pipe when running?

Check your coolant level. And drain your trans fluid to see what it looks like.

Water can't enter the crank case or cylinder from a leaky crank seal, but trans oil will.

The yz has 3 typical entry points for the coolant. Head gasket, base gasket or oval o-ring between the cases.

I would bet though, if you were pressure washing your pipe, you shot some into it.

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Water can't enter the crank case or cylinder from a leaky crank seal, but trans oil will.

The yz has 3 typical entry points for the coolant. Head gasket, base gasket or oval o-ring between the cases.

I would bet though, if you were pressure washing your pipe, you shot some into it.

True. I was getting at the possiblility of his w.pump impeller leaking into the tranny, then getting sucked through the cc seal. That happened to me, and that's what trans+coolant looked like coming out the pipe.

OP, I agree with the others: run it for a bit, see what happens, probably just water. Keep an eye on that coolant level for a bit tho.

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is it coming from the hose that connects to the powervalve? if so, mine does the same thing. i beleive its not a problem

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is it coming from the hose that connects to the powervalve? if so, mine does the same thing. i beleive its not a problem

No, your referring to unburnt premix (spooge) from the vent hose... That is def water.

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I have the exact same thing going on with my 01. It just started out of the blue. I am going to be tearing it down either this weekend or next. Keep us posted!

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