Engine light knock

[Worz]

After a lovely long dry summer I finally bit the bullet & took the lump out of my 12,000 mile fzs600, the local dealer and a number of mates were all flummoxed by the noise, so after checking all the usuals timing chain, valve caps etc I began stripping the engine, just hoping to find the source of the noise.
To my amazement once the barrel was off no3 big end was as loose as a dick in a bucket, somewhat relieved to have found the cause of the light knock, but very surprised to find on such a low mileage lump.
No other obvious signs of oil starve & no play or wear in any of the other journals.
Any thoughts ??.....…

[Gav]

Wow yeah not good for 12k.  However, great you found it and I know what it's like to that huge relief feeling.

[Dave48]

Either a breakdown in the pressurised oil supply or faulty/incorrect size big end bearing shell?
While engine stripped check entire oil supply system-strainer,pickup,oil pump,oil feed jets,pressure relief valve but I imagine faulty oil supply would affect more than one set of shells.
Re bearing shells-any clues from code numbers?- see relevant section in Haynes manual.- assuming engine has never been dismantled from new this points towards incorrect size/clearance from original assembly?

[Worz]

Cheers dave, will pay close attention to all that, does look like engine hasn't been stripped before, bores are like new and no oversize stamps on any shells text
Thanks
Worz