KE100 holed piston

Hi all, my son sold his Ke100 yesterday to a nutcase. On the testride he thrashed it and when he left he was doing the same. I'm guessing it was flat out most of the way home!!!!
Problem is he blew a hole in the piston, refunded all bar £50 at his request.
Obviously i have taken the head off and seen the hole, plug is shot to.
The bore looks good, so i have ordered a top end kit, standard size.

heres the question, do i strip the engine completely to make sure there are no bits in the bottom? or should i take a chance the bits went through the exhaust?.
Saving me lots of time and effort.
Your opinions please.
Oops bike has done 12k, i suppose it was due a top end anyway
atb Red

ke 100

Hi Red when you have barrell off put a little oil on crank and turn over slowly bits should stick to crank you can pick them off you should split cases but i've had quite good results like this

For the size and effort I would take the motor out of the frame suspend it over a parts washer upside down and turn it over by hand using the little end at the same time using the jet from the washer to rinse out the casings.
That way you should guarantee all of the bits come out.