I totally agree with what floatingwind suggests. My further suggestion: You are NOT the decision maker, you got to remove this illusion completely. You are neither in favor nor against HIS decision.
Write an email (and print a copy for future reference, keep it in a safe place) to your boss:
provide your professional judgement based on your expertise; tell him the possible consequences that might be caused by the KNOWN defects ( you've told him before, correct? ). Keep your points strictly in your professional domain, make it objective.
Push the ball back to his court. That's the way to cover your butt.