Strange leak at cylinder top

[tudorv]

Hey guys. Found this after a long ride today. Any idea what it is and why it's leaking? From what I can tell there are no real gaskets up there. Only silicone ones. Bike runs absolutely fine by the way. Is this a cause for concern?

Thanks!

[jonathan180iq]

How old is this bike?

It looks like it has some miles on it, but there is a common leak on these bikes from that area. Remove the chrome cover you see there and spray your warm engine with some degreaser. Give it a little scrub with a stiff bristled brush and it should clean right up.

What that particular seepage is, we don't really know. It's very common though.

[alantf]

I had seepage along one of the fins. I took it to the bike shop, and the mechanic tightened up the head bolts. I've had no repeat since, and like you, the bike was running fine.

[blaine]

It looks like it may be leaking from the valve adjustment cover.(small cover with 2 bolts) It has a o-ring in it.As Jon stated remove the chrome cover so you can clean it up & have a closer look.
:cool:

[PimpS]

Similar to mine... The leak went from the top of the cylinder head, it was not a gasket. Mechanic put off the tank and the top, put some paste for sealing and off the bike went... I had a thread about it and member here (polish guy, can't remember his nick name...) Wait... I'll paste the link.. Rynr was his nick BTW...
viewtopic.php?f=7&t=5932&start=25

Hope it will help you!

PimpS

[tudorv]

Thank you for your replies! The bike is from 2004 with about 20.000 km on it. Could this leak be related to the fact that I adjusted the fuel-air mixture the day before?
The pilot screw was only one rotation out. Now it's set a 2 rotations and a bit out. Did I mess up?

[alantf]

Like blaine said... check that the valve cover isn't leaking oil. There should be an O ring under the lid. It may have perished over the years, or it may just need tightening.

[jonathan180iq]

Originally Posted by tudorv

Thank you for your replies! The bike is from 2004 with about 20.000 km on it. Could this leak be related to the fact that I adjusted the fuel-air mixture the day before?
The pilot screw was only one rotation out. Now it's set a 2 rotations and a bit out. Did I mess up?

No. Your pilot adjustment didn't suddenly cause slight oil seepage. No worries here.

This ugly brown goo stuff usually occurs earlier in the life of the bike. But you don't have too many miles on her anyway.
I suggest giving it a good cleaner with degreaser, going for a ride with that chrome cover removed and seeing if you can pinpoint the location of the seepage. It's not that bad, and degreaser is an awesome cleaner anyway. It will wash away all kinds of stuff and you will clearly be able to see where this is coming from.

[raul10141964]

my leak from the valve Agustin covers some RTV silicon solved

[OldNTired]

Originally Posted by tudorv

Hey guys. Found this after a long ride today. Any idea what it is and why it's leaking? From what I can tell there are no real gaskets up there. Only silicone ones. Bike runs absolutely fine by the way. Is this a cause for concern?

Thanks!

Had that problem with mine (2006). Since I had a reason to dig into the engine for a different problem, I scraped the old sealer from the bottom of the head cover, cleaned it, and applied a good sealer. That was it, and no problems with it since. The old sealer had a weak spot there, 'maybe' due to position: very near the exhaust valve, meaning a lot of heat in that area.
As a quick fix try, just tighten the bolts going into the head cover; it might stop it.