100 hp Johnson '68 - Gears won't shift.

[Jbones1969]

I've been fiddling around trying to figure out why the gears aren't shifting on a friend of mines boat. Has a 1968 johnson 100 hp, and right now, it doesn't want to shift out of neutral. After taking the lower unit off and rewiring everything, applying power via battery, and testing it, we found the lower unit is fine, and the gears would shift, however, after putting the lower end back on, and testing it out, she would just rev, but not shift into forward or reverse, any ideas would be amazing.

 

[tashasdaddy]

Re: 100 hp Johnson '68 - Gears won't shift.

are the wires connect correctly? did you check the shift switch for power? did you route the wires so they would not rub the drive shaft and short out? i've seen a couple where the wires were worn thru by the drive shaft.

 

[Jbones1969]

Re: 100 hp Johnson '68 - Gears won't shift.

Could it possibly be caused by using other than Type-C oil? I'm at work right now and, like I said, it's not my motor, so I don't know what he put in it. Or could it be caused by a bad ground?

 

[F_R]

Re: 100 hp Johnson '68 - Gears won't shift.

Correct oil is important, but probably not the problem. Check the voltage at the blue and green wires (connected). Should be 12V on green for forward and on blue for reverse. Under no circumstances ever allow the blue and green wires to contact each other when running. It will bust something as it tries to go into both gears at the same time. If it flunks that test, check all wiring, especially the shift switch. If the switch is bad, use only an Electromatic switch, not the Hydro-Electric one for the same reason mentioned about going into both gears at once. The Electromatic switch is over $400, if you can find one. I have a new one if you need it, but at less than $400.