Cylinder wash out

In your experience, how rich is too rich where youll start having the fuel wash away the lubrication on the cylinder bores? Main reason for asking is, taking a start from scratch tune and not having worked on a similar set up, and once started, you're say 10%-15% richer than target. Would that cause the bores to wash out and eventually lead to problems?

In all honesty in 20 odd years in this industry I've yet to see an engine that's genuinely been damaged by bore wash. Yes it is possible but very rare and would take an extended period of time in order to happen. You definitely won't have the engine damaged if you're running it a touch rich while you're getting the tune dialled in. If you're very rich then you're more likely to have issues with the plugs fouling than any actual bore damage.

Ok I didn’t know if the bores getting washed and the oil nearly becoming fuel (petrol) if that would start causing issues for the bores or bearings etc due to heat. Just figured I’d ask the question for a better knowledge base