‘77 Johnson 70hp Starter Troubleshooting

[HerrGruyere]

Hi!

I have a ‘77 Johnson 70hp (70el77s). She’s sat for 20 years. Last year with a crap battery, I got a couple of weak turns when engaging the starter. This weekend, I got a new battery and nothing happened when turning the key. Some things to note:

Cleaned all connectors to super shiny (terminals from battery to solenoid, battery to ground, solenoid to starter, etc.).

Choke engages when pushing key.

I get 12V at the solenoid from the battery.

I get 0V when key is turned to start. I may have measured wrong, though. I put the pos lead on terminal to battery and negative lead on solenoid to starter.

No clicks or hums from solenoid.

Taking the lead from battery and touching to starter lug does nothing but spark.

Cracked open the remote control and didn’t find a neutral safety switch. No wiring is on the motor that I can see near the gear levers.

Sprayed connections with WD-40.

My guess here is bad starter and solenoid and possibly a bad ignition switch. Just checking with the experts to make sure I’m on the right track. Please let me know if I’m missing something. I’ve scoured the Internet but getting mixed results.

Thank you!!

 

[saltchuckmatt]

See if you can manually turn the starter with a wrench.

Is it 12 volts (which is a dead battery) or did you get 12.6 or 12.7 volts? That's a full battery.

 

[HerrGruyere]

See if you can manually turn the starter with a wrench.

Is it 12 volts (which is a dead battery) or did you get 12.6 or 12.7 volts? That's a full battery.

12.6-12.7 at the battery. Within .2 at the connections.

 

[racerone]

Replace the wee ground wire from solenoid to the block.----Find the neutral switch in the control box.----Or maybe some one took it out.----Find the wires and tell if they are connected.

 

[HerrGruyere]

Replace the wee ground wire from solenoid to the block.----Find the neutral switch in the control box.----Or maybe some one took it out.----Find the wires and tell if they are connected.

I think someone removed it or it never existed. I’ve tried jiggling the lever real good while holding the key and nothing happened. There are no things plugged in or resting near the cams on the inside.

Ground wire from solenoid to block is a good idea. I have some wire laying around I could use.

 

[racerone]

When it left the Johnson factory there was a neutral switch in the control box.----I can not see or touch your motor.----Here it would be easy to solve this puzzle !

 

[HerrGruyere]

When it left the Johnson factory there was a neutral switch in the control box.----I can not see or touch your motor.----Here it would be easy to solve this puzzle !

I bet I could see once I get it off the side of the boat. Gotta find the bolts on the inside.

I have a starter and solenoid (both returnable) on the way.

 

[tphoyt]

While your waiting for parts squirt some oil in the cylinders and turn the flywheel by had for a couple minutes a day. if she’s been sitting for 20 years they will enjoy the massage.

 

[HerrGruyere]

Wrong starter arrived :/

I cleaned up all the grounds. I ran a small jump from the terminal from battery to each one of the small nuts (“I” and “S”). Nothing happened. While my daughter held the key on start, I checked with a multimeter (correctly this time!) from battery terminal to “I” and “S”. I think “S” had nothing and “I” had the voltage (I was in a hurry). Battery still measuring healthy with key held down. 12.6V anywhere voltage measured. I also spun the starter with a wrench and it turns nice and free. Checked the cables for crunchiness, and they are all pliable. Jiggled the everliving mess out of the shifter while holding start. Turned the motor a whole bunch, too. Nada.

My new solenoid arrives tomorrow. We’ll see if that works. There is a black cable running under the flywheel. It’s connected to the throttle linkage. I can’t quite access it. Looks pretty clean, but could that be my bad ground?

Is it also possible to just bypass the neutral switch in the remote control by bridging the two wires from the switch?

One last thing: could I move the neg ground off the post on the manifold to one of the starter mounting bolts? I was getting some flicker on the multimeter when checking stuff. This might also explain why nothing happens when I jump the starter.

 

[racerone]

Find the wiring diagram online !-----The " lets see what happens if I hook up this wire "----Can create smoke and cost you big money.

 

[Jeff J]

“Cleaned all connectors to super shiny (terminals from battery to solenoid, battery to ground, solenoid to starter, etc.).”

What about the nuts, bolts, washers and engine surfaces where these connectors connect?

 

[HerrGruyere]

“Cleaned all connectors to super shiny (terminals from battery to solenoid, battery to ground, solenoid to starter, etc.).”

What about the nuts, bolts, washers and engine surfaces where these connectors connect?

You know it! Cleaned those nice and shiny, too.

 

[saltchuckmatt]

Wrong starter arrived :/

I cleaned up all the grounds. I ran a small jump from the terminal from battery to each one of the small nuts (“I” and “S”). Nothing happened. While my daughter held the key on start, I checked with a multimeter (correctly this time!) from battery terminal to “I” and “S”. I think “S” had nothing and “I” had the voltage (I was in a hurry). Battery still measuring healthy with key held down. 12.6V anywhere voltage measured. I also spun the starter with a wrench and it turns nice and free. Checked the cables for crunchiness, and they are all pliable. Jiggled the everliving mess out of the shifter while holding start. Turned the motor a whole bunch, too. Nada.

My new solenoid arrives tomorrow. We’ll see if that works. There is a black cable running under the flywheel. It’s connected to the throttle linkage. I can’t quite access it. Looks pretty clean, but could that be my bad ground?

Is it also possible to just bypass the neutral switch in the remote control by bridging the two wires from the switch?

One last thing: could I move the neg ground off the post on the manifold to one of the starter mounting bolts? I was getting some flicker on the multimeter when checking stuff. This might also explain why nothing happens when I jump the starter.

If your doing a direct feed from the battery to the starter and it doesn't do anything your starter is no good.

 

[HerrGruyere]

For anyone following this:

New solenoid arrived but that was a waste of time. I guess I’m too strong and the plastic housing cracked when I was tightening the I and S nuts. I put the old one back on.

I took apart the remote control. I’m getting 12.5V at the ignition switch on the purple wire. I tested the resistance of the neutral safety switch (I found it!) and it was good. I was getting 12.5V through it. Everything is fine there.

Still getting 12.5V at the I and S on the solenoid when start switch is on. I also get 12.5V the top lug to the starter. The ground wire for the solenoid looked wretched. It was all dull and flaky. I tried soldering a bit of it to no avail.

I’m gonna pick up a length of wire and some lugs to make a new ground wire. I also ordered new battery cables to be on the safe side. The new starter arrives tomorrow. If the darn thing doesn’t start tomorrow, I am literally all out of ideas.

Edit: And by “start” I mean crank. I’ve installed new spark plugs and a new impeller, but no guarantees it’ll run. Just trying to get it to crank at a minimum.

 

[CaptnKingfisher]

For anyone following this:

New solenoid arrived but that was a waste of time. I guess I’m too strong and the plastic housing cracked when I was tightening the I and S nuts. I put the old one back on.

I took apart the remote control. I’m getting 12.5V at the ignition switch on the purple wire. I tested the resistance of the neutral safety switch (I found it!) and it was good. I was getting 12.5V through it. Everything is fine there.

Still getting 12.5V at the I and S on the solenoid when start switch is on. I also get 12.5V the top lug to the starter. The ground wire for the solenoid looked wretched. It was all dull and flaky. I tried soldering a bit of it to no avail.

I’m gonna pick up a length of wire and some lugs to make a new ground wire. I also ordered new battery cables to be on the safe side. The new starter arrives tomorrow. If the darn thing doesn’t start tomorrow, I am literally all out of ideas.

Edit: And by “start” I mean crank. I’ve installed new spark plugs and a new impeller, but no guarantees it’ll run. Just trying to get it to crank at a minimum.

If you don't have one of these they are very handy when troubleshooting stuff by yourself. https://a.co/d/e3EhEy5
Hook one lead power and another to the crank pole on the solenoid and you can be standing at the engine checking things while sending power to crank. You ought to see on that solenoid that when you are putting power to crank that the pole from battery to starter is continuous and energized. If youve got that and you've got good grounds (and starter does nothing) then the starter is toast. You could also remove the solenoid and bench test it in a similar fashion.

If you want to test your grounds set your meter to continuity and find where the battery ground lands on your outboard and with the other lead touch each point where things should be grounded. It should ring out with no resistance. I'm all for replacing and cleaning grounds that don't look great but you can have confidence in your diagnostics by actually using a tester rather than just visual guessing. It will allow you to move forward if you know that these grounds are OK

 

[saltchuckmatt]

For anyone following this:

New solenoid arrived but that was a waste of time. I guess I’m too strong and the plastic housing cracked when I was tightening the I and S nuts. I put the old one back on.

I took apart the remote control. I’m getting 12.5V at the ignition switch on the purple wire. I tested the resistance of the neutral safety switch (I found it!) and it was good. I was getting 12.5V through it. Everything is fine there.

Still getting 12.5V at the I and S on the solenoid when start switch is on. I also get 12.5V the top lug to the starter. The ground wire for the solenoid looked wretched. It was all dull and flaky. I tried soldering a bit of it to no avail.

I’m gonna pick up a length of wire and some lugs to make a new ground wire. I also ordered new battery cables to be on the safe side. The new starter arrives tomorrow. If the darn thing doesn’t start tomorrow, I am literally all out of ideas.

Edit: And by “start” I mean crank. I’ve installed new spark plugs and a new impeller, but no guarantees it’ll run. Just trying to get it to crank at a minimum.

12.5 to the starter... it should be cranking. Pull the starter apart and examine it. Might just need a cleaning and a new brush kit.

 

[HerrGruyere]

12.5 to the starter... it should be cranking. Pull the starter apart and examine it. Might just need a cleaning and a new brush kit.

Solenoid doesn’t click, either. Something doesn’t add up.

 

[HerrGruyere]

If you don't have one of these they are very handy when troubleshooting stuff by yourself. https://a.co/d/e3EhEy5
Hook one lead power and another to the crank pole on the solenoid and you can be standing at the engine checking things while sending power to crank. You ought to see on that solenoid that when you are putting power to crank that the pole from battery to starter is continuous and energized. If youve got that and you've got good grounds (and starter does nothing) then the starter is toast. You could also remove the solenoid and bench test it in a similar fashion.

If you want to test your grounds set your meter to continuity and find where the battery ground lands on your outboard and with the other lead touch each point where things should be grounded. It should ring out with no resistance. I'm all for replacing and cleaning grounds that don't look great but you can have confidence in your diagnostics by actually using a tester rather than just visual guessing. It will allow you to move forward if you know that these grounds are OK

The new (and correct!) starter gets here tomorrow. Plus new battery cables. I forgot to note the solenoid does not click.

I don’t mind having a helper turn the key. It makes them feel like they’re a part of it.

 

[saltchuckmatt]

Solenoid doesn’t click, either. Something doesn’t add up.

Car jumper cables...engine ground last connection. It has to work.

Post a picture of these parts.

 

[Crosbyman]

choke works so fuse is ok ..... T&T should work if you have one

no solenoid clicks... check B+ from Key S post in START MODE .neutral
possible solenoid inside winding could be open or solenoid badly grounded

apply direct B+ on solenoid control post if OK backtrack to switch S post
if not OK bad solenoid or bad ground

has stated apply B+ from battery to starter IN post ... if OK backtrack to solenoid issue