1969 55 hp Johnson hung in forward

[dhunter]

I have a 1969 55 hp Johnson. i have fire at the silinoids but it is almost like it is hung in forward. also the motor has been sitting up for almost 12 years buts runs like a champ other than that sifting problem. If anybody has any suggestions on this i will really appreciate it thanks in advance.


dhunter

 

[Beek14]

Re: 1969 55 hp Johnson hung in forward

Can you shift it out of forward? Does this shift go back and forth as its supposed to? If not you may have some lower unit problems. You should definately check the gear oil from the gearcase. If it has been sitting for 12 years, and didn't have any oil in the case, all the gears and everything else would probably be quite rusted up by now, and would leave you with quite the bad news. I hope that's not the case but I would definately check if it shifts, and the gear lube!

 

[jay_merrill]

Re: 1969 55 hp Johnson hung in forward

I'll offer my standard advice - go buy a service manual for your specific motor. Original Equipment Manufacturer (OEM) manuals are available right here at iboats. See the "Marine Store" tab, above.

Your motor has a hydro-electric shift system. It is designed to remain in forward, unless hydraulic pressure directs a piston in the gearbox to select either neutral or reverse. Failure of the piston to move as it should, could be the result of a defective component in either the electrical system or the hydraulic system.

Since the proper gear oil for your motor is one of those components, you could start there. Your gearbox requires "Type C" gear oil, which is currently referred to as "BRP Premium Blend." If there is little or no gear oil in the gear box, that is possibly the source of your problem. If the gear oil seems to be a bit on the thick side, it could be the wrong gear oil. Oil that has a gritty feel to it, could be contaminated with sediment. rust or metal particles. After sitting for so long, you could also have a piston that is jammed.

Go ahead and get the OEM manual - it will make troubleshooting for all of the possible sources of your problem easier.

 

[tashasdaddy]

Re: 1969 55 hp Johnson hung in forward

have to agree with Jay. also the Motor has to be running for it to shift. the drive shaft has to turn the oil pump in the lower unit.

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 "Premium 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.