I seem to have stripped my oil plug (83 KZ550) - just hoping somebody could tell me whether the Kawasaki engineers used a plug metal that was softer than the oil-pan metal - I'm worried. Suggestions?

 

I have not seen that one yet. Good for you that the plug is the one that went and not the pan threads. Are you sure that you did not cross thread the bolt on the oil change? (bad thoughts....) How was the washer condition for the pan/bolt? Welcome to KF

 

Check oil pan threads with a bolt/plug of the correct thread diameter/pitch. If it won't go in (using finger pressure) you may have residue in the oil pan threads which you may be able to clear using a tap of the correct diameter/ pitch. If their is a problem in both respects you may be able to get the pan "helicoiled".

gammac

 

I replaced it with the same 12/1.5 plug from NAPA and all seems okay- got lucky. What a lummox...

 

Good advice from gammac^. You DID get lucky. Always finger-tighten the first few threads on filters, plugs, drain plugs, etc. I've done that same OMG on aluminum Land Rover heads on the plugs next to the firewall (which are inaccessible to humans) and have the taps and thread restorers to prove it.
WHEW! Glad to hear things worked out.
Welcome to the forums, bd.
Gear up; stay safe.