|
I don't think the S4R has an o-ring between barrel and crankcase although I believe there is one at the top end of the cylinder head studs.
Have you established exactly where on the head the leak is from? If not, thoroughly clean and degrease the area and try to spot from where the oil escapes. If it's from one of the studs, it could be the top o-ring (assuming it has one!).
Alternatively, is it from the mating surface between the head and barrel? That would sound like a head gasket (any white steam in the exhaust or 'cream' in the oil?).
Don't overlook the cam cover gasket either - if the cover's been off a few times and the gasket's original, it may be due for a change.
Aren't there also covers on either side of each head with their own collection of o-rings?
Seems like there are quite a few opportunities for leaks all told! (I think I'll stick to my obsolete two-valver!).
Let us know what you find. Hope it's not too involved/expensive.
|