Strange hydro electric shift problems

[4runneradam]

'72 Johnson 100hp. Boat and motor sat in someones yard for 15 years until I rescued it last week. Motor had the cowl on it and seems just fine. Turns over just fine, has compression (still need to test it)

I drained the lower unit (nice clean gear oil came out) and refilled it with dex/merc ATF due to low funds and availability of Type C.

From what I've read here, to make the unit shift into reverse, you apply power to both green and blule wires, and to go to neutral you put power to green.

Here's what I'm doing and what happens.

Using a car battery and jumper cables, I ground the engine block, apply a jumper from positive on the battery to one of the connectors on the starboard lower side of the powerhead that have the rubber insulation pushed back (did not actually disconnect them just put an alligator clip on them) Then applied power to the positive terminal on the starter and turned her over.

With no jumper to the shift wires, prop turn clockwise. (forward?)

Green wire jumpered, she turns counter clockwise (reverse?)

Blue wire powered, she turns clockwise (forward)

Green and blue wires powered together, she turns counter clockwise (reverse?)

Whats going on here? I can't get neutral, and she turns in reverse when she is supposed to go into neutral.

I'm also trying to do a compression check. I have all the plugs pulled, and she turns over OK while doing the above test. But as soon as I put my compression tester on and try to crank, I get about 60psi and it wont crank. I'm sure I'm supposed to be putting her in neutral to do a compression check but I cant get there.

 

[jbjennings]

Re: Strange hydro electric shift problems

Here's about all I can tell you. When the motor is working correctly, the prop will spin momentarily and then it will go into neutral and not spin any more. Every time you start the motor, it will start off in forward. If your motor will spin over freely by hand with the plugs out and not feeling any roughness when you rotate the flywheel, then if it won't spin over very fast under compression it's likely that you have a bad starter or bad connections somewhere. There is a way to put your own switch for the shift, if your shift switch is bad, but it's not ideal and if you do it wrong, will ruin the motor. As far as the compression test, if the starter is turning it over with full power with plenty of speed, it shouldn't matter if it's in or out of gear. I'm not sure, but I think the motor has to build hydraulic pressure in the lower unit before it shifts out of forward which is the reason it always starts in forward gear. Again, I'm not sure, but it may not be possible to get neutral with that motor without the motor actually running or spinning over.
I hope this helps at least a little.
JBJ

 

[4runneradam]

Re: Strange hydro electric shift problems

I guess I've got a bad starter. It wont even turn the motor over with all the plugs in. Its a good battery, I pulled it out of my truck. It only drops to 11.2v when it tries to crank, so it should be turning over.

I guess I'll just sell it without hearing it run.

Whats a good asking price for this motor?

 

[jbjennings]

Re: Strange hydro electric shift problems

I'd ask 200 bucks for it. It's just a parts motor if it's not running, in my opinion. One thing---- I got a used starter that works great for $30 on ebay for my '72 50hp motor. I had the same problem you're experiencing. You could probably part your motor out and make 4 or 500 on it if you were willing to go to that trouble.
JMO,
JBJ