Oil Injection System Removal
The mercury oil injection system is a popular item to remove, especially given its reputation for failure, and inability to deliver reliably after 6500 rpm.
Remove oil resevoir, oil pump, mag pickup, pump drive shaft, then install plug in shaft hole. Remove oil hose off bottom of vapor seperator, plug hose, remove fitting on starboard side of the block where oil tank pressure hose is coming from, plug hole with pipe fitting either 1/8 or 1/4., Remove oil alarm box, and i think that's all. the plug for the pump shaft hole you will have to get from dealer. (12)
Mercury part number for the plastic block off plate is 43453 and the O-ring for that kit is 32509. Jay Smith Racing Engines also has a billet kit for doing this.
Finally it is recommended by several sources, that you keep the old oil pump gear on the crankshaft, as it provides crankcase volume, and if removed will cause that cylinder to be lean.