Cylinder head "o" ring

[PaulD]

As most of you know I'm collecting all the bits ready to rebuild the top end of my motor this winter. I've got a genuine Suzuki head gasket coming from club member spondonchris and I've ordered valve stem deals from Robinsons however, the motor is weeping oil from the front right hand corner of the head to barrel joint (as you sit on the bike) I've heard this is a common fault and fitting a new "o" ring cures it but my parts book doesn't show an "o" ring? Chris is selling two head gaskets and one of them appears to have rubber "o" rings as an integral part of the gasket. My parts book lists different numbers for the 1100Z & D, I'm assuming my bike is a Z (unpainted motor) so can anyone shed any light on what I need and if I need the "o" ring do I need 4 (one for each corner) or just one and what is the size/part number?
Thanks in advance and I'm sorry for bombarding you all with fact questions

[johnr]

the o ring that causes problems isnt actually on the head or th gasket. because of the layout of the engine the central cylinder head studs that hold the engine together have to be accessed from under the camshaft area with the cam cover off. however the studs go from the 'wet' part of the head, that is, inside in the oil sprayed interior of the engine, down through the barrel into the open air before going into the top of the cases. as a result, the nuts that secure the head on this wet part of the engine have a shoulder on them which is machined to take a o ring that stops the oil from running down the stud and thus into the open air and then as its at the front, being blown backwards covering the engine. so if you look at the microfiche the nuts securing the head in the centre studs have o rings round them to keep the oil in. these are often overlooked on rebuilds and the heat makes the o rings harden shrink crack and wear letting the oil out.

and never be afraid of bombarding the forum with daft questions, tbh the forum probably needs the traffic......

[johnr]

the other thing that can case leaks is the rubber 'D' shaped cap at the end of the cam. these are best given a smear of wellseal when they are fitted to keep the oil in.
having said that, some early engines had an intrinsic fault tat suzuki knew about. if you look at the rocker cover, early ones are secured by 20 bolts, later ones by 24 bolts. the extra four being added on the front and rear either side of the camchain tunnel as the cover flexed enough in use to allow oil to weep out. not a great deal you can do if your engine is a 20 bolt. use wellseal on the gasket on assembly and torque it to the factory settings and cross your fingers, because to fit a 24 bolt cover will require the later 24 bolt cylinder head!

[PaulD]

Thanks John, I know the D shaped rubbers are good as I replaced them when I did the valve clearances. I think the "o" rings you are talking about are part number 09280-17002 or number 17 on the diagram and I need 2 of them, is that correct? There are also four "o" rings that wrap around the cylinder liner as they protrude from the bottom of the barrels (part number 09280-74002) is it worth replacing those? I only want to do this job once