antifreeze in the exhaust pipe 02 yz 125?

[CR_Racer]

I am rebuilding the top end on my 2002 Yamaha Yz 125 and when I took off the exhaust pipe about half a cup of antifreeze poured out of the pipe how did this happen is this normal all the clyinder gaskets were fine?
Also when I move the power valves one moves and the other one does not are the springs worn out?

 

[oldfrt613]

Anti-Freeze in the exhaust pipe - oh, that cant be good :( ! We had a like problem with a KTM - porosity in the head allowed anti-freeze into the exhaust even though the gaskets and o-rings appeared fine.

 

[Blue 250]

You probably had a pin hole in the base gaskit or in one of the o-rings for the head. Both should open just by taking pliers and turning the shaft. What kind of oil did you use and how many hours are on this topend? Its possible that one could be gummed up and has to be removed and cleaned. The springs shouldn't affect how PV opens. I would rebuild it and run new gaskits and check if your antifreeze level has dropped and dont forget to properly torque all the nuts down to spec. Hope this helps some.

 

[BigRedAF]

Bummer!

I suspect the head o-rings first of all.

The valves should move unless they are carboned up. Have you had this top end off before? Have you ever R & R a top end before? If not get some help from a friend, it's not a very complicated job.

Taking apart the power valve and it's related parts can be a chore for a first timer, just make notes and don't force anything. Clean them with carb cleaner and a mild scruber, something like scotch brite.

New gaskets and o-rings and you should be fine. If you have milky transmission oil then you have a bigger problem than bad head o-rings.

Good luck!

 

[CR_Racer]

I think it must be the o ring gasket it was melted and alittle thinner then the new one. The oil was clean when I replace the oil I also had the bike in a shed in -15c then moved to a warm garage where it will stay for good.
I have alot of hours on the bike 35 hours most of it trail riding I think I left it a little too long but the clylinder looks good and the piston is not too bad but it is time for a new piston and rings.
I tryed to remove the power valve but they are stuck in there I don't know how to get it out the valve move when I push on it with my finger it is just the casing is stuck in there any tricks on getting that out.

 

[BigRedAF]

It been a few days, if you haven't got to it yet you can spray it with carb cleaner and it will dissolve the goo enough to allow you to pull it out. Don't use EZ-Off, it will goof the aluminum!