Help Help, pistons hitting crank, what would cause this?

Hi everyone I recently rebuilt the top and bottom end of my 04 Honda CR250 because the pistons was hitting the counter weights of the crank. Upon completing the rebuild I was inspecting the the old components I found that neither the connecting rod bearing or wrist pin bearing had any up/down play so my question is what would have caused the piston to make contact with the crank counterweights? Please lmk your guy’s thoughts

Thanks~Matt