Cylinder head oil

[Shooter]

Hi
I have just noticed I've got a ring of oil where the cylinder head meats the cylinder. Any ideas where it's come from?

[john r b]

Looks to be a new set of o-rings are in order.... or need to be put on order lol
any sign of coolant. have you over heated the bike?? Head bolts torked to spec??

[Shooter]

I had thought it was only coolant then ran around the cylinder head. Am I wrong as normal lol. Will be torquing tomorrow it think. There is no sign of coolant leaking out and I did get it very hot the trip before last

[Jakobi]

Coolant runs through the water jackets in the cylinder and head. The o-rings stop the coolant from leaking in both directions. If the inner o-ring fails, the coolant runs into the cylinder and burns off. You then run out of coolant and/or overheat. This in turn can warp the cylinder/head/cook the other o-ring and then exhaust gases and oil/spooge can cross under pressure past both o-rings and out the head.

My first check would be to see how much coolant is in your bike. Next stop 2 new o-rings and check if the head and cylinder are still true. Piston dome should tell story if its been washed clean by coolant/overheated.

[Shooter]

Thanks. I'll get some o rings on order