I have a 5 hp Merc outboard I bought with my boat used. It's from somewhere between 1989 and 1994. While using it to motor over to the lift crane to have my boat taken out of the water yesterday, I came across a new problem (new to me).The motor has a shift rod in the lower unit that moves downward when shifted into reverse. When this shaft is all the way down, a spring-loaded tilt lock is supposed to engage, preventing the motor from tilting up when underway in reverse. Now, even though the shift lever is all the way back, the rod will not go down far enough to allow the tilt lock to engage. Result? I had to physically hold the motor down in order to get the boat backwards into the crane slip. Not a permanent solution.Any ideas on the cause and solution?