Electric shift 1970 115hp no nuetral or reverse

cnixon

Cadet
Joined
Aug 26, 2005
Messages
22
Today I got the old girl on the water and had the first "real" voyage. It wouldn't idle or run at low RPM, but I think that is to be expected when it has set as long as this one has. You may remember earlier post that determined lower unit was siezed. That is fixed, and it performed well until I came in, suddenly I lost neutral and reverse. Shift solenoids were working earlier, and was shifting. Were should I start looking, control box? Solenoids? any help would be great. Also, how concerned should I be about a tankful of fuel that is 18 - 24 months old. Could that create my idle/low RPM run problem, or should I start thinking about carb work?
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Electric shift 1970 115hp no nuetral or reverse

(Hydro Electric Shift)<br />(J. Reeves)<br /><br />The shifting setup of the 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. 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 />In reverse, you need 12v to both wires, the "Green" one and the "Blue" one. <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.
 

cnixon

Cadet
Joined
Aug 26, 2005
Messages
22
Re: Electric shift 1970 115hp no nuetral or reverse

Thanks Reeves, that is what I would call excellent instructions. I now know aqlot more. I did use the correct fluid, this guys here made sure I knew that prior to removing and reinstalling my lower unit. Any thoughts about the old fuel?
 

djzyla1980

Chief Petty Officer
Joined
Jul 26, 2005
Messages
640
Re: Electric shift 1970 115hp no nuetral or reverse

I'm thinking your getting water in the lower unit somewhere.... Drain the lower unit and see if it's milky. If the LU oil isn't correct or it has water in it... it will only go in forward(defualt) My problem was the seal to the seleniods... but most common are the round seals to the vent and plug holes...
 

djzyla1980

Chief Petty Officer
Joined
Jul 26, 2005
Messages
640
Re: Electric shift 1970 115hp no nuetral or reverse

About the carb work... If I recall it sounded like the previous owner took good care of this motor... I would suggest putting fresh fuel in it before looking at carb work... most fuels are only good for about 30-45 days... <br /><br />The carbs a cake to rebuild... just look at the manual. Also checking the plugs would be the next thing I do
 

cnixon

Cadet
Joined
Aug 26, 2005
Messages
22
Re: Electric shift 1970 115hp no nuetral or reverse

Ok Dave, Thanks. You are correct, the guy did take good care of it. I will try new fuel. I will also check fluid tommorow. I am on vacation this week and will spend my time working on her till she runs right, then shining on her till she looks right, when thats all done I will fish her till vacation is over.
 

dhud64

Petty Officer 1st Class
Joined
May 2, 2003
Messages
344
Re: Electric shift 1970 115hp no nuetral or reverse

...when thats all done I will fish her till vacation is over.
Yeah right, does Nader know that? :) <br /><br />If you have my luck, vacation will be over first!!!
 
Top