I also own a johnson 90hp only mine is a 2001. It to left us stranded on the water when the power pack quit in the same manner yours did. The motor would turn and fuel was not the problem but when I checked for spark at the plugs their was none at any of the cylinders. I purchased a power pack after consulting a seloc manual on how to troubleshoot the problem. You must also replace the optical sensor along with the power pack. trust me on that part cause I wound up buying another power pack cause I wasnt told that important info.