forward gear on 72 Johnson 85hp outboard

[mclark4642]

hey guys,

I asked a question a while back about a problem I had going forward when I took my boat out on the lake, but I didn't have any problems going in reverse. You guys were very helpful and I just wanted to follow up.

I marked the prop to check for a spun hub, and then took it out on the lake again, and this time it moved forward without any problems at all! So I suspect at this time, it is not a problem with a spun hub.

However, a few days later, I started the motor with water muffs (because I was going to show it to a prospective buyer) and I noticed when I moved the lever into forward, the prop didn't turn at all. I then dropped it back into neutral and this time, moved the lever into reverse. The prop started turning with no problems. Finally, I moved the lever back into neutral, and then into forward, and the prop started turning again.

Do you have any ideas on what the problem might be? I am not a mechanic, but I'm just wondering if there is a loose connection within the shaft of the motor that might keep it from clicking into gear sometimes. That's just a guess since I don't know what the inside of the motor looks like

 

[tashasdaddy]

Re: forward gear on 72 Johnson 85hp outboard

bad shift switch in the control, you have a hydro-electric shift motor, inside the control is a round switch that has a lever on it, when in neutral it has this lever in one position, in reverse another, in forward the lever is released, it sounds like the neutral switch is not releasing some times. this motor when there is not power to the solenoids, in the shift unit, automatically goes to forward.

here is a full explanation of the 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

 

[mclark4642]

Re: forward gear on 72 Johnson 85hp outboard

okay thanks! I guess I should probably just take it in to a mechanic? Hopefully, it's not expensive, and it could use a tune-up anyway. I would like to sell it without putting much more money into it, but it seems to be hard to sell when I tell them that it needs a tune-up, even though I'm asking a ridiculously low amount anyway.