JOHNSON 50HP 1972 HYDRO ELEC DRIVE

[blake]

I HAVE RECENTLY PURCHASED THIS ENGINE CHEAP AND HAVE 2 QUESTIONS, DOES ANYBODY HAVE A SCHEMATIC DIAGRAM FOR THE ELECTRICS FOR THIS ENGINE ALSO SHOULD I BE ABLE TO TAKE OUT OF GEAR WITH OUT FIRING IT UP, E.G TURN OVER ON STARTER OR BY HAND AS I CANT SEEM TO GET IT OUT OF FORWARD. ANY DIAGRAMS OR PICS WOULD BE MOST APPRICIATED. BLAKE PLEASE FORWARD TO B L A K E . G R E E N @ N S N . C O . U K

 

[Barnacle_Bill]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

It has to be running to take it out of gear. You should get a manual for it. Best investment you can make and it will pay for itself with the first repair you make.

 

[Barnacle_Bill]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

Lower unit also has to be full of type c or premium oil or it will stay in fwd gear even when running..

 

[R.Johnson]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

To add to the confusion on these hydro-electric's, there are no spring loaded clutch's used as in the electro-matic's, it is a straight, gear driven gear case, the hydraulic pump simply shift's it in, and out of gear. Heavy oil, if used can make it sluggish if used in cold water. I had a 1972, 125 on a 15'5 ft. Checkmate. It had a jackplate set as high as it could go running a Raker prop. I used Hi-Vis in this gearcase when it became available, and as long as I owned the boat, which was until this last summer. It never gave any problem's, as it was alway's in faily warm water. I could push this engine to over 6000 RPM.As I said above, this is a straight gear driven case, the same as any other later model.

 

[F_R]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

I tried to send you a wiring diagram, but it was rejected. Something wrong with your e-mail address?

 

[blake]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

thanks to everyone for your help most appriciated, try my other email address g r e e n _ b l a k e @ h o t m a i l . c o m, also does anbody know what manual this under as i have search but can only find manuals 50 hp + with 3 cylinders not 2 like i have...?

 

[F_R]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

 

[Joe Reeves]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

(Hydro Electric Shift)
(J. Reeves)

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.

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)

In neutral, you need 12v to the "Green" wire.
In reverse, you need 12v to both wires, the "Green" one and the "Blue" one.
In forward, there should be no voltage to either wire. (The spring loaded shifter dog forces the unit into forward gear)

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.

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).
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.

 

[R.Johnson]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

Joe: Not to argue with you here, but I ran Hi-Vis in mine for a good many year's without a problem. I ran that engine hard, and wanted the better lube

 

[Joe Reeves]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

RJ..... You were one of the few lucky ones then. The oil pump or simply the screen itself is not designed to handle the heavier HiVis lube. Trust me, it calls for the Premium Blend, formerly known as Type C.

 

[R.Johnson]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

Joe: I agree! those were certainly the recommended oil's. My engine only seen river use run over the summer month's, so cold water was not a problem. As I recall there was a service bulletin on this matter, I'll see if I can find it. The only problem I ever had, running this engine jacked up, with a 24" Raker, it crracked the prop shaft bearing carrier.

 

[Jmuddin284]

Re: JOHNSON 50HP 1972 HYDRO ELEC DRIVE

is there any way to change this lower unit to a cable shift? or are there any cable shift type lower units that will work on this motor?

Jmuddin284