1977 Johnson 15 HP Unable to Stop Engine

[Jasmar]

My Johnson 15 Hp Stop button does not Stop the Engine. I took the switch apart and clean the contacts, It does make continuity when depressed. as far as I could go back to the first connector, I unplug the wire and test the continuity. One wire goes to ground and the other continues to a Black Module in the back side of the motor.

I am assuming that the switch grounds something in the module and kills the engine.

Help

Tom

 

[tashasdaddy]

Re: 1977 Johnson 15 HP Unable to Stop Engine

you are correct in your assumption. could be bad switch, or broken wire. corroded connection.

 

[nightstalker]

Re: 1977 Johnson 15 HP Unable to Stop Engine

Check where the ground wire connects to the engine block. I had the same problem a couple of weeks ago. I cleaned the ground connection at the block and that fixed the problem
Nightstalker

 

[joho5]

Re: 1977 Johnson 15 HP Unable to Stop Engine

if anything else, you would need to check under the flywheel to see how the connections are under there with the points / condensers.

 

[Jasmar]

Re: 1977 Johnson 15 HP Unable to Stop Engine

Thanks for the input so far, Tahadaddy, Nightstalker, and Joho5(no points or condenser on a 1977, apparently they stop using points and condensor in 1974, per Johnson dealer)....but thanks.

Analysis so far:

1. Switch does work, continuity at the first plug between the two wires when the stop switch is depressed.

2. Cleaned the Ground wire at the block and the block area also, good contact now.

3. The other wire runs to a module and the wire does not appear to be broken. I could cut the wire just before it goes into the module and check continuity between first plug and there, but looking at the wire it looks good and not pinched or crimped.

4. I would assume that the module is bad, any ideas? If so, does anyone know if the module is very costly. Can someone please discribe what the module does? Secondly, it seems to basic that somewhere in the module this wire would ground out the spark and kill the engine? If it is that simple, what could go bad in the module to prevent this?

5. If nothing else, pull the chock out kills the motor. Funny thing I was able to kill it but by just turning the throttle down to idle before, but I just fixed the idle adjustment knob and t works great...perfect Idle....won't die, ha ha.

Any additional advise would be greatly appreciated.

Tom

 

[ezeke]

Re: 1977 Johnson 15 HP Unable to Stop Engine

You should have a 3 wire amphenol plug leading to your powerpack.

The black and yellow wire within it is the kill wire. Before you waste money on a new powerpack, check the kill wire by grounding it to the engine block with the engine running. Use a needle through the wire if necessary.

 

[Jasmar]

Re: 1977 Johnson 15 HP Unable to Stop Engine

ezeke

Clarification.

Based on what you are saying just ground the yellow wire to kill the engine. If this works, then could I connect black wire that comes from the switch (one not going to ground) to the yellow wire outside the power pack to kill the motor or would that cause problem.


JASMAR

 

[ezeke]

Re: 1977 Johnson 15 HP Unable to Stop Engine

It (kill wire) is a black wire with a yellow tracer stripe.

The switch has two wires, one of which is grounded to the engine block. Pushing the button completes the circuit and grounds the powerpack, preventing firing and instantly stopping the engine.

If you can replicate that effect by going around the switch, than the problem is not the powerpack.
If grounding the powerpack kill wire does not stop the engine, the powerpack is faulty.

 

[Rick.]

Re: 1977 Johnson 15 HP Unable to Stop Engine

If in the end you find the kill switch is faulty, ask me about a retrofit lanyard kill switch I put on mine. If your interested. Rick.

 

[Jasmar]

Re: 1977 Johnson 15 HP Unable to Stop Engine

Rick,

I am interested. Tell me, thanks
Tom

 

[Rick.]

Re: 1977 Johnson 15 HP Unable to Stop Engine

For safety sake I got interested in the idea of installing a lanyard kill switch. After checking things out I purchased one from a manufacturer called Sea Dog. I simply removed the original button kill switch snipped the wires very close to the kill switch and crimped on two stake on connectors to the original wires and then mounted them to the new kill switch. I used the washers from the original switch and the sea dog fit the hole very well. Now when the lanyard is pulled off the switch the motor dies. Makes me feel safer and I won't have near as much concern with my kids using the motor either. The whole job went very well and very quickly.
http://www.dickssportinggoods.com/p...683&siteID=q5QZHUbCIj8-IFA5Vceo409n55b7anMACg
This is the one I used (universal with normally open and normally closed contacts) and oddly they are available at Toys R Us in the U. S. I got mine at an OMC dealer in Canada. Rick.

 

[Jasmar]

Re: 1977 Johnson 15 HP Unable to Stop Engine

Rick,

Thank You for the information. Once I am able to determine what prevents my Stop Button from killing the engine and I will install a lanyard kill switch. Since I know the Stop switch does have continuity when depressed, but does not kill the engine, the lanyard will not either. I will try the test recommend at the power pack today and see if is the power pack or the wire from the first plug to the power pack is the problem. Thanks Again

Tom