1987 Johnson 150gt Spark issues

[jrgrady]

I have a 1987 150gt that is not sparking. I unplugged the black/yellow wires to each powerpack and I get spark on all cylinders. My book said if that happens to replace the keyswitch and kill switch on the control box. Did that and still no spark. I tested the ground connection between the 2 m terminals on the back of the keyswitch and the kill switch and key are working properly. I then checked the ground signal by unplugging the black/yellow wires at the powerpack and I was getting a ground signal when using the keyswitch which is what I want right? The ground signal kills the ignition when you want it to shut off. What am I missing??

 

[dingbat]

Re: 1987 Johnson 150gt Spark issues

You tested the grounds on the terminals at the back of the switch and found what? They should be open as should the black/yellow connection in the "run" condition..

 

[boobie]

Re: 1987 Johnson 150gt Spark issues

Agree +1...........You're doing something wrong some place. Wish I was there.

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

I was receiving continuity (ground) between block ground and the black/yellow wire when I had the keyswitch in the off position or when the lanyard was pulled. Im under the impression that when I want to shut the engine off, the keyswitch sends a ground signal to the black/yellow wires on the powerpack.

 

[boobie]

Re: 1987 Johnson 150gt Spark issues

That is correct.

 

[emdsapmgr]

Re: 1987 Johnson 150gt Spark issues

Are you testing with the plugs in/out? Does the engine crank at least 250 rpm's? It won't make enough voltage to fire the ignition if it is not cranking at least 250.

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

Are you testing with the plugs in/out? Does the engine crank at least 250 rpm's? It won't make enough voltage to fire the ignition if it is not cranking at least 250.

I wouldn't think it mattered if the plugs were in or out. I get spark with the black/yellow wire unplugged with the spark plugs in. I really am at a loss on what to look at next.

 

[dingbat]

Re: 1987 Johnson 150gt Spark issues

I was receiving continuity (ground) between block ground and the black/yellow wire when I had the keyswitch in the off position or when the lanyard was pulled. Im under the impression that when I want to shut the engine off, the keyswitch sends a ground signal to the black/yellow wires on the powerpack.

what happens with the key on? Does it go away at the blk/yel wire?
Have you checked to make sure the neutral switch Is functional?

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

what happens with the key on? Does it go away at the blk/yel wire?
Have you checked to make sure the neutral switch Is functional?

Yes, when the key switches to run position, the ground goes away. I'm going to go out today and unplug the red harness plug and jump the solenoid to see if I get spark. At least then I can isolate the problem to the remote control.

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

I'm going to go out today and unplug the red harness plug and jump the solenoid to see if I get spark. At least then I can isolate the problem to the remote control.

So I went out and unplugged the red plug and jumped the solenoid to turn the engine over. No go on spark. My understanding is that these motors only need the battery to turn the engine over and that the magneto actually powers everything when its running/cranking. Now I'm even more confused as that rules out the remote control box. So now are my power packs both shot? That doesnt make sense.

 

[boobie]

Re: 1987 Johnson 150gt Spark issues

Sounds to me like some bad wiring on the motor. If you unplugged the black/yellow wires from the packs and the red plug disconnected did you have spark then ??

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

Sounds to me like some bad wiring on the motor. If you unplugged the black/yellow wires from the packs and the red plug disconnected did you have spark then ??

Yes. Im confused now. I checked the grounds on each power pack and they were good. What else could I be missing? Thanks for the comebacks by the way....

 

[boobie]

Re: 1987 Johnson 150gt Spark issues

Sounds like the black/yellow wire is grounded someplace between the packs and the red plug on the motor.

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

Sounds like the black/yellow wire is grounded someplace between the packs and the red plug on the motor.

So the one half of the black/yellow wire goes directly to the power pack and the other side goes over the engine to the red plug. If I'm getting the proper ground signals from the keyswitch to the plug end at the yellow/black plug, could it be 2 bad power packs or no because when I unplug the black/yellow plug Im still getting spark. At this point, I'm ready to cut the black/yellow wires and wire in my own switch which would manually ground the engine to shut it down. I can't brainstorm the problem for the life of me.

 

[out 2 launch]

Re: 1987 Johnson 150gt Spark issues

When you test the resistance in the Black/Yellow wire from the engine through the switch to ground (WITH THE SWITCH IN THE RUN POSITION) what ohm meter setting are you using to verify an open circuit to ground? You must use the highest range setting available, any continuity, even at a very high level of resistance can kill the packs.

 

[jrgrady]

Re: 1987 Johnson 150gt Spark issues

When you test the resistance in the Black/Yellow wire from the engine through the switch to ground (WITH THE SWITCH IN THE RUN POSITION) what ohm meter setting are you using to verify an open circuit to ground? You must use the highest range setting available, any continuity, even at a very high level of resistance can kill the packs.

My fluke meter does an auto range.