1971 johnson electric shift

papa_dan2002

Recruit
Joined
Jun 1, 2002
Messages
3
I HAVE A 1971 50HP ELECTRIC SHIFT MOTOR. THE SHOP SAYS IT WORKS WHEN YOU PUT MUFFS ON IT BUT WHEN YOU PUT IT IN WATER IT WILL NOT GO FORWARD. IT WORKS GREAT IN REVERSE. ANY HELP WILL WORK. IS THERE AJUSTMENT OR ANY THING I CAN TRY PLEASE HELP
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 1971 johnson electric shift

Dan.... Hopefully the following will help you somewhat.<br /><br />The shifting setup of that lower unit is what's called a "Hydro Electric Shift", which is quite complex consisting of voltage being applied to solenoids in the lower unit which in turn change oil passages via a oil pump that supplies various pressure on a spring loaded shifter dog.<br /><br />The wires leading to the lower unit (at the powerhead) are "Green" and "Blue". The engine must be running or cranking over in order to shift out of forward gear.<br /> <br />You CAN NOT use HI VIS lube in that lower unit. You MUST USE what OMC calls "Preminum Blend" lube, commonly called "Type C". (A thinner lube) <br /><br />In neutral, you need 12v to the "Green" wire. <br /><br />In reverse, you need 12v to both wires, the Green one and the Blue one.<br /> <br />In forward, there should be no voltage to either wire. (The spring loaded shifter dog forces the unit into forward gear) <br /><br />To check the lower unit for proper shifting to make sure you have no trouble there, remove the spark plugs to avoid problems and to allow a higher cranking speed. <br /><br />This next step eliminates the actual shift switch in case problems may exist there.... Disconnect the blue & green wires at the knife connectors (the rubber insulated boots) leading to the lower unit at the powerhead, then using jumpers, take voltage direct from the starter solenoid to apply voltage to the "Green" wire for neutral, then both wires 'Green" & "Blue" for reverse (Remember the engine must be cranking over in order to shift).<br /> <br />With no voltage applied, the unit should be in forward. No need for a ground jumper... the lower unit's already grounded. You may crank the engine with the key switch or by energizing the starter solenoid with a jumper wire.
 

b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
Re: 1971 johnson electric shift

oops.................on that lastpost...........I had and old omc outdrive with electric shift that had the same problem. It turns out that someone made a splice below the water line to the shift wires, so when it was in the water a short was created. I found this out while standing in the water and grabbing the wire !!!(12v can pack a hell of a punch) But out of the water it shifted fine……I spent hours of tracing wires before I found out. After I fixed the wire it worked :) fine.
 

papa_dan2002

Recruit
Joined
Jun 1, 2002
Messages
3
Re: 1971 johnson electric shift

captin thank you that is more than we knew. when i got the boat the lower unit was dry. could the pump be out of it? all i found was milk.
 

Franki

Lieutenant Junior Grade
Joined
Feb 16, 2002
Messages
1,059
Re: 1971 johnson electric shift

you found milky substance in the lower unit where the oil should be??<br /><br />You have problems,,,, thats usually due to water mixing with the oil...<br /><br />look for bits of metal or other substances in there.. if so, Its probably clagged.<br /><br />I had a problem with the pump blocked and I flushed it with premix and refilled, it worked.<br /><br />Do not confuse the cooling water pump with the oil pump in the lower unit.. very different, its very very unlikley someone has taken the pump out of the lower unit since thats a big job, and why would it be reassembled without it?<br /><br />The oil pump is the one Mr Reeves was reffering to.<br /><br />firstly, do his tests on the unit.. (after flushing out the old oil and replacing it.) <br />see how bad things are.. if it works fine, go for an outing and see if the lower unit oil turns white again.. if it does, then you have to replace the seals. if you don't, you will end up trashing your lower unit altogether. it was not designed to run with water in it :)<br /><br />rgds<br /><br />Frank
 
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