I hope I have better luck in this form.
I have a 150cc motorcycle motor that has seized due to running out of oil.
The piston rod seized to the pin running through the piston.
I have ordered a new head so all will be new except the piston rod, which I cannot replace unless I disassemble the entire motor, and the piston rod doesnt disassemble, it is a pressed crank shaft assembly, So I would have to buy the entire thing.
Ok now to the problem at hand, I want to recondition the piston rod for the new pin and piston. The rod has a 15mm bore about .75 width, there are to holes driller into the center of the bore, I assume for allowing oil into the center of the piston rod/pin assembly.
Upon expanding/shrinking when it overheated there is a score mark inside the center of the bore where the expanding pin or shrinking piston rod caused the 2 oil holes to act as cutters and cut a grove in the pin which cut a grove in the piston rod.
I need the best solution to get this back to a polished surface for the pin.
My thoughts were to possibly run a 15mm reamer back through the bore and lap or polish it, or possible since the bore is smooth except for the center to get a round stone or sintered rubber impregnated tool and just remove the score mark to below the rest of the bore and lap/polish.
We do not do any finishing at our machine shop, so I do not no the best materials/tools to get this back to usable polished condition, any help would be appreciated.