Oil leak from the petrol pump

[Reckless Rat]

I've got a slight leak like that, Peter, but not from the bottom of the valve chest. It seems to puddle on the moulding that creates the trench on the other side for the gasket, so I'm wondering if it's actually coming from the retaining screw/cover interface. Either that or it's blow out from the venting holes being blown back by the 4 blade fan, but I doubt it because the engine is recently rebored. I have "modified" the fixing screw to see if that sorts it, using a fibre washer and a circle of silicone (belt & braces).