Anyhow, the upshot of the drama was that the sump (and presumably all the oil passageways) got contaminated with a HUGE amount of unleaded, enough to take me completely by surprise when i tried to drain it out. It's been run at least for a couple of minutes in this state, if not a good mile or two. I did change the oil, but with hands covered in cack and lacking my usual tools i wasn't able to get the filter off.
What might be the consequences of having run it in this state for even a little while? Is it destined to death (about 1000 miles after coming out of it's overhaul running-in period!) or will it be ok now? As the mixture was still distinctly "oily" may it have been sufficient protection for low revs at low temperatures? And what of the filter, will it have purged ok, will it have re-contaminated the oil enough to be a concern --- or will any remainder have been burnt off gradually in the cylinders?
Thanks....