[methodical]

Simply put, if he's not carrying his weight and doesn't seem passionate, kick him off of the project and return to doing whatever duties you assigned to him yourself. He clearly doesn't care much about it, and from experience in a very similar situation, no amount of speeches will impact his motivation in any long-term way. You're simply opening yourself up to more disappointment and frustration, not to mention potential ownership issues by continuing to allow him to come along for the ride. As harsh as it sounds, this is why people don't go into business with friends, unless you are completely fine with that friendship not lasting on the other side.