1971 Johnson 100hp Shift Issues

[oregonfish]

Hey All,
First boat in a long time, and it's shaping up to be quite the project! I'm sure I'll be visiting this board a lot My first question is about the electric shifting. For starters, I have no idea how this system really works. I have the lower unit off and have located the bits and pieces in there, but don't understand how they make the gears shift.

The motor seems to be stuck in neutral. I don't get purposeful prop movement at all. I also took the controls apart. The switch is what I'm assuming is responsible for shifting into forward, reverse and neutral. I am curious if the little arm with the roller on it is supposed to be spring loaded so that it maintains contact with the circular part of the shift lever. Right now, the lever moves the arm in one direction or the other, and then the arm just stays there. Either way, this arm seems to have no impact on the shifting. What are the best ways to trouble shoot this system?

I'll stop with one rambling and confusing post for now. Thanks everyone for looking and I appreciate any help!

Chris

 

[F_R]

Re: 1971 Johnson 100hp Shift Issues

Well for one thing you need a shift switch. As you suspect, the arm is supposed to folow the lever. Hang onto your chair when you find out the price. IF you can even find a new one, that is.

The switch should supply battery voltage to the green wire when in neutral and to both green and blue wires when in reverse. No voltage to either wire when in forward. You do know how to check that with a multimeter, right?

EDIT: It won't do anything unless the motor is running. It will always be in forward gear if not running. That is a built-in safety feature. If anything goes wrong with the system, it goes into forward gear so you can get home. Usually.

 

[oregonfish]

Re: 1971 Johnson 100hp Shift Issues

Thanks F R! I do know how to test with the meter. Will do that tomorrow. I had already priced a replacement, and...yeah...that hurts! There must be some way to rig that up, right? The switch is more expensive than the boat!

So the switch only operates with the motor running? It won't work with the key in the "on" position?

How does that system actually cause the gears to shift? Do the solenoids move up and down when powered? They seem to be free moving inside the lower unit. Is that normal?

Again, thanks for the help!!!

 

[F_R]

Re: 1971 Johnson 100hp Shift Issues

A search will find volumes written on the subject, but here goes one more time: The motor is NOT "electric shift". It is "Hydro-Electric Shift". The shifting is done hydraulically. The switch and solenoids only operate a couple of flow control valves that direct the oil to do the shifting. There is an oil pump in the lower unit that provides the hydraulic pressure. Obviously, the pump cannot work if it isn't rotating (running). When it is not running, a spring forces it into forward gear.

 

[oregonfish]

Re: 1971 Johnson 100hp Shift Issues

Thanks again, F R. Very helpful info!