Exhaust Leak from power valve? YZ125

Hi All,

I've got a '94 Yamaha YZ125. There is a breather tube coming out of the
exhaust power valve that typically drips excess unburned oil.

The other day I started it in cold weather and noticed exhaust coming from
the breather tube. (It was pretty obvious as the exhaust was blue-grayish
color). I have never noticed this before, nor do I figure this tube should
be leaking this much exhaust as its just a thick rubber tube (If this were
to be normal I'd expect the tube to be made of a hi-temp tube).

The exhaust never stopped coming from the breather tube throughout my ride.
The bike still made normal power and ran well. I did not notice any thing
out of the ordinary or experience any other problems.

Can anyone point me in a direction to start with? (just in case it helps,
I've included some of the recent motor work that has been done at the bottom
of this post)

Thanks!
Ed
egradek.RemoveThis@hotmail.com
or
eddie at captainbeer dot com


A few months ago, I needed to redo the top end after the ring broke. The
cylinder needed to be re-sleeved as the nickel plating around the cylinder
wall was flaking off.

With about 25 minutes on the new top end, during the break in ride, a lower
rod bearing went out, which in turn ruined the top end again. This problem
was not apparent/did not exist while rebuilding the top end just days
before.