1972 Evinrude 85hp Stuck In Forward

bolter15

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Jun 2, 2008
Messages
27
Just started work on an old Hydro Electric shift Evinrude...

The lower unit seems to be stuck in forward at the moment. But the shift button is giving good voltage to the shifter leads, and I hear the very faintest click when I apply voltage to the leads with a hand switch. (ear pressed up against the lower unit)

I took out the old gear lube and it ran down the case a lot like hot honey.. It made me think I had the wrong kind of lube in the case for a while.. There was also a funny two tone character to the oil that was coming out of the case. It's like the oil in the front part of the bullet case had turned dark and the oil in the back of the case was still light colored. And much more like the stuff I used to refill the gear case.

The engine was stored sitting on it's face on the ground with the propeller pointed up. so the light stuff was probably floating on top of the dark stuff.

It takes three tubes of type C gear case oil to fill this puppy up.

I was very surprised that the motor started right up and ran for me. And I was hoping that a few more revs might persuade the pump and the shifting plunger to operate normally. But that hasn't happened yet. So I think I'm looking at a lower unit tear down perhaps.

If anyone's got any ideas about what to try first, or things not to try, let me know. I was thinking of launching the boat and running the whole system under load for a short while to see if more reves might help free things up. I didn't see any signs of metal in the oil pan. It might be ordinary gunk corrosion doing this..

Oh, and the motor does not shut down with the key. I've got some kind of short in the wire harness to track down. With the key on, I get power to four of the screws on the junction bar. And with the key off, I get power to one of the screws on the junction bar.. So what wire in what system could short to keep the motor going when you turn the key off?? (When the key itself and the wiring up to the power head is acting normally?)
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 1972 Evinrude 85hp Stuck In Forward

Just started work on an old Hydro Electric shift Evinrude...

The lower unit seems to be stuck in forward at the moment. But the shift button is giving good voltage to the shifter leads, and I hear the very faintest click when I apply voltage to the leads with a hand switch. (ear pressed up against the lower unit)

I took out the old gear lube and it ran down the case a lot like hot honey.. It made me think I had the wrong kind of lube in the case for a while.. There was also a funny two tone character to the oil that was coming out of the case. It's like the oil in the front part of the bullet case had turned dark and the oil in the back of the case was still light colored. And much more like the stuff I used to refill the gear case.

The engine was stored sitting on it's face on the ground with the propeller pointed up. so the light stuff was probably floating on top of the dark stuff.

It takes three tubes of type C gear case oil to fill this puppy up.

I was very surprised that the motor started right up and ran for me. And I was hoping that a few more revs might persuade the pump and the shifting plunger to operate normally. But that hasn't happened yet. So I think I'm looking at a lower unit tear down perhaps.

If anyone's got any ideas about what to try first, or things not to try, let me know. I was thinking of launching the boat and running the whole system under load for a short while to see if more reves might help free things up. I didn't see any signs of metal in the oil pan. It might be ordinary gunk corrosion doing this..

Oh, and the motor does not shut down with the key. I've got some kind of short in the wire harness to track down. With the key on, I get power to four of the screws on the junction bar. And with the key off, I get power to one of the screws on the junction bar.. So what wire in what system could short to keep the motor going when you turn the key off?? (When the key itself and the wiring up to the power head is acting normally?)

A blown (shorted) shift diode between the ignition switch and the shift diode will prevent the motor from turning off. That was the easy part.

Your shift problem could be oil or electrical related. From your story, it sounds like oil related. Like the oil pump is all gunked up or worn out. Same for the shift valves. Those units don't like dirty oil. $$$ time.
 

bolter15

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Joined
Jun 2, 2008
Messages
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Re: 1972 Evinrude 85hp Stuck In Forward

Thanks for the tip on that diode. You were right! The cool part is that when I chipped away all that resin they had on that little beast and got good heat shrink on the wires with melted insulation, the diode itself was good. It just needed new wires on it.

I pulled and checked the diode on the back of the motor too. It's numbers were just a little low. I used a cheap harbor freight multi meter so I never really trust my numbers with that stuff. The diode setting is supposed to read out up around 600. My numbers were like 550 - 450. Just a little bit off. I'll have to figure out what that means later.

The diode itself looked like the cap to a tube of oil paint. It was heavy. Silver colored. about as big as 4 or 5 dimes stacked together. I'm looking into what kind of $2 diode I can replace that with. Of course, they want $60 for the part and can't get it to you for a week.

If they hadn't bunched up the wires to make it look "scrote like" the part wouldn't have failed. A wad of chewing gum with wires coming out of it. they should have been more careful about how they ran the wires out of the resin. they put all the hot wires in one place with nothing between them but a little insulation.
 

phipps

Petty Officer 1st Class
Joined
Jul 20, 2008
Messages
385
Re: 1972 Evinrude 85hp Stuck In Forward

I have a '71 60hp Johnson that doesn't currently run. I'm pretty sure it is the amplifier. The lower unit is good so if I can't get it going I'll have some hydro-electric parts.
 

bolter15

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Joined
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Messages
27
Re: 1972 Evinrude 85hp Stuck In Forward

Gunk in the lower unit you say??

Dirty oil and such??

I'm wondering if the lower unit case could be filled with a solvent and left to soak over night. And if that might just un-gunkify things.

But I also noticed in the manual that the screen on the front of the oil pump was held on with an adhesive. This could be just to hold it there while it was installed.

So what would happen if the adhesive on the screen failed??

Has anyone here ever installed one of these pumps before??
 

pmat1

Petty Officer 1st Class
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Jul 9, 2009
Messages
332
Re: 1972 Evinrude 85hp Stuck In Forward

Anyone ever run seafoam through a lower unit? :D
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 1972 Evinrude 85hp Stuck In Forward

Gunk in the lower unit you say??

Dirty oil and such??

I'm wondering if the lower unit case could be filled with a solvent and left to soak over night. And if that might just un-gunkify things.

But I also noticed in the manual that the screen on the front of the oil pump was held on with an adhesive. This could be just to hold it there while it was installed.

So what would happen if the adhesive on the screen failed??

Has anyone here ever installed one of these pumps before??

Yeah, "gunk" as in dirty oil, water, chips, anything but nice clean oil. Really tiny metal wear particles are the worst (well actually water is the worst). But the almost microscopic metal particles that manage to get through the screen will cause jamming of the shifter piston in the oil pump bore. That is why they said to drain and refill the gearcase regularly. Once the piston/pump is jammed, nothing will get the offending particles out short of tearing it down. But I gotta say they more often jammed in neutral because it relys on the spring to push it back to forward.

But go ahead and flush it with some mineral spirits or something, can't hurt and might help.

Yeah, I've had a few of them apart, but admittedly it was over 30 years ago. So, I don't remember any adhesive on the screen (????). The screen is held on with a screw.
 

bolter15

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Messages
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Re: 1972 Evinrude 85hp Stuck In Forward

Adhesive was mentioned in one of the clymer manuals regarding the screen. Didn't make much sense to me.

This unit was sold as a running motor to someone who tried to start it in a hurry. It wouldn't start for him and he fried the starter. Then he gave up on the motor and it sat for many months. It did not fail while it was in use. So I do not suspect foreign material in the lower unit such as wear particles. I think it's possible someone topped it off with the wrong sort of oil in the lower. But I'm not sure of it.

I keep planning to get it down to the river and run it at full pressure for a while, then see if it shifts. If I just open it up and let that pump really pump for a while, it might clear itself.

It hasn't been run in a long while, and I'm suspicious of the water pump. Can anyone venture an opinion about my three options for a new water pump impeller?? Evinrude, Mallory, or Siera?? Who makes a good pump?? Are they all about the same??
 

bolter15

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Joined
Jun 2, 2008
Messages
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Re: 1972 Evinrude 85hp Stuck In Forward

Last night I put a meter on the shifter leads for just one more check. And I found something out of the ordinary. They both were reading about 6 ohms resistance, but then I tried reading voltage passing through the coil and found that one was passing the full 13 volts and the other was only passing about 5 volts.

I abandoned the notion that both coils were good and pulled the lower unit right there.

The Neutral shifter coil was dead. Very dead. So I switched the two coils and re-assembled the unit and took it for a ride. It now has forward and Neutral. And it moves my little boat like a bomb!

It's not that it goes so much faster really. It just ignores the fact that the boat is fully loaded. There used to be about a five mile an hour difference between one person in the boat and two. Now there's almost no difference at all.

I'm tempted to call it good right there. Boats are meant to go forward. Not having reverse seems fairly easy to accomodate with a little extra boat handling savvy.

But I did find a good solenoid out at Island Marine Salvage for $40 so I might as well install it. It's nice to know that the little hydraulic shifting pump is working.
 

bolter15

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Jun 2, 2008
Messages
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Re: 1972 Evinrude 85hp Stuck In Forward

Forgot to thank all you guys on the board! Thanks!!

I knew nothing about this lower unit before I read about it here.

I did fill the gear case with mineral spirits and leave it over night. I left the solvent in when I re-assembled the motor, and I turned it over a few times before I drained it and put in type C.

I think I had success on this motor where another guy didn't because I left the motor over night with fuel in the carbs. (in stead of filling it with fuel, buying a new battery and cranking it until the starter died)

Thanks again
 
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