I have a 1970? Johnson 9.5 Short shaft. Recently I discovered 2 of the 4 bolts holding the lower unit in place were missing. One I discovered is broken off; the other appears to be stripped (cannot insert bolt completely into threaded hole). <br /><br />My plan is to remove the lower unit and take the basic casing (engine) to a machine shop and have the bolt(s) tapped out and holes made to the next size up.<br /><br />Questions: Is this feasible? Is any other work required? How do I remove the lower unit from engine (aside from removal of remaining bolts)?<br /><br />Can you confirm year of engine (Model #MQ 13M; Ser. # J2 762633)