Yanmar YSB8 strange oil leak

[Spyro]

Looking for suggestions
My engine starts and runs fine it will run for hours with no sign of an oil leak however when the engine is stopped and the boat is under sail and healed to starboard It starts to leak oil, (no leak if healed to port) just a few drips but enough to make a mess it appears on the bottom of the rocker cover I think it may just be coming from the rocker cover gasket but it must be at the back where I can't see it coming out. First question is why does it only leak when not running and healed to starboard and second is it only one bolt in the centre of the rocker cover holding it on. Third is there any difficulties removing the rocker cover such as the decompression lever mechanism under the cover.
Any suggestions appreciated!
(the Ysb8 has a horizontal cylinder)


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[sailorman]

i seem to remember a breather pipe on the rocker cover i.e stbd side, this short steel pipe should have a plastic pipe taken up above the engine.

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[GrahamC]

YSB8 rocker cover has only the single nut which is captive on the cover by a circlip
inside. No problem with the decompression lever when you take off the cover. The arm makes contact with the exhaust valve only when the valve is closed, and is held clear when running by the return spring. When you have the cover off, check the valve clearance when your in there, gaskets available from E P Barrus if required.
regards
GrahamC

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