bit of muck in there or possibly a ring breaking up due to improper use (check my sig for the piston view)
personally i wouldn't i'd have new p+r for it. and flush the bottom end if there are any bits of debris missing from the piston.
No they aren't, theres plenty more metal where that came from! It'll just go bang if you use it any more. It'll happen when it's raining, and somewhere you have to leave it where it'll get nicked. At least you have the bike somewhere safe to work on it at the moment.
that's optimism! but he's right, my rs did simelar, i flushed the bottom end out and the parts washer fluid came out silver, such a small peice of piston was chipped but it spread everywhere. i flogged the bike very soon afterwards.
lol yeah, one carefulowner and 7 tear arses i beleive judging by it's mechanical condition even before i got it. plastics were nice though
best bet is to strip the top-end, fill the crancase with petrol, spin the crank, and drain 3 or 4 times. then drop loads of oil on the big-end and around the mains and re-build with new piston and rings, assuming the barrel is ok.
you can risk it if you want but the chances are you will be needing a crank and mains within 500 miles if you don't
ill be doing all the work thats why i have my own bike to worry about when it finally gets paid out imp:
sorry but could you explain roughly how to flush out the crankcase please? i mean, like is it a big job, or would i be able to do it myself? cheers guys