1971 Evinrude Starflite 100HP- Hydra shift

[crestlinermusky]

A friend has just purchased a 1971 Evinrude 100 HP with hydra electric shift.
The motor runs great but won't shift, stuck in Neutral. I know the motor defaults
to forward when a solenoid goes and the engine is shut off. Have read all the posts
dealing with this type of motor. Does anyone have an idea where to start looking for the problem.

Mark

 

[F_R]

Re: 1971 Evinrude Starflite 100HP- Hydra shift

There are only two possibilities: Electrical and hydro-mechanical. If there is no voltage presence at either of the blue/green wires going down to the lower unit, it has to be a mechanical problem in the gearcase. Likewise, if it is in neutral when not running, it has to be a mechanical problem. That would seem to be the situation as you describe it. So....a mechanical problem means a lower unit teardown. Trash (fine grit) in the piston that moves the clutch dog is the likely culprit. That's what happens when you don't change the oil often.

 

[hdluvrs]

Re: 1971 Evinrude Starflite 100HP- Hydra shift

Well I have a question along these lines. I have a 1971 evinrude 100 hp starflite with the hydro-electric lower unit and it will not go into forward, even when disconnecting the leads. It goes into reverse and into neutral just fine...therefore the solenoids should be fine. Where do I go from here? Oil pump? then reverse shouldn't work, right? Is there something that when neither solenoid is activated that holds the forward gear in place?