You want to flush all the debris from the piston failure out of the crank case which is the area you picked the pieces out of, the gear case is under where the oil fill plug is located, this is totally seperate from the crank case on a 2 stroke like yours. But run the diesle thru the crank case, rotate the crank a few times, dump out diesle pour some more in, and repeate this untill it looks like no more material is coming out with the last rinse.