Still, still stuck with no spark

[Merccoper]

Hi all.
I posted a thread about this last year and still struggling with it, so reaching out again for help. I’ve done additional test steps, but to summarize:

On my second trip out on my new to me 1996 Mariner (see signature for detail) my engine just quit. No sputter, coughs or bangs. Stopped just as though I turned the key off. I’m not getting any spark on all 4 plugs. I have followed the service manual to do diagnostics. I have bought a DVA to do the testing.

- Checked all plugs (using an inline spark tester).
- Stator ohm’s tests ok.
- Stator volts at crank ok.
- Trigger ohms ok.
- Switch Box (new box installed).
- Each Ignition coil ohm’s tests ok.
- NO voltage at any ignition coils when cranking.
- Ignition key switch tests ok ( I did a continuity test between the switch and wiring harness at the engine. Also tried starting it by jumping Red, yellow\red and purple wires on the widening harness plug on engine side. Cranks ok but no voltage at ignition coils)
- There is no tilt stop switch
- There is no kill switch.

based on the above, the service manual still says it’s the switch box. I’m hesitant to replace it again. Seems like it could be something else. But I’m stuck.

I was wondering if possibly the neutral switch was messed up. But I’d that was the case, the engine wouldn’t even turn over….I would think

Not sure where to turn to now. Any help would be very much appreciated

 

[Chris1956]

Are you getting stator voltage at the switchbox when cranking? You might disconnect the spark killer wires (black/yellow) at the switchbox, to remove the ign key from the test.

You obviously need a spike of voltage at the coils, when cranking, however, a standard multimeter is usually too slow to react to see it.

 

[stresspoint]

not knowing the model of your motor , it may have a "stopper switch" .some early motors had them but not sure if the eliminated them on 96 motors.

 

[stresspoint]

disclaimer , i only know enough about Mercury /Mariner outboards to keep me from paying for work to be done on the ones i have owned .

 

[Merccoper]

Are you getting stator voltage at the switchbox when cranking? You might disconnect the spark killer wires (black/yellow) at the switchbox, to remove the ign key from the test.

You obviously need a spike of voltage at the coils, when cranking, however, a standard multimeter is usually too slow to react to see it.

Thanks for the suggestions. yup, I’ve removed the black/yellow from the switch box.

regarding the multimeter, I bought the DVA to attach to the meter in order to read the voltage. Voltage from the stator is good. No voltage is coming out of the switch box into the ignition coil.

 

[Merccoper]

disclaimer , i only know enough about Mercury /Mariner outboards to keep me from paying for work to be done on the ones i have owned .

Lol, that’s about my knowledge too!
regarding the stopper switch (or the kill switch and or the tilt switch, the motor doesn’t have them.

 

[Chris1956]

Coil grounds are clean and tight?

If you have stator voltage into switchbox, and no spark out, either switchbox is bad or trigger or wiring are bad.

 

[Merccoper]

Coil grounds are clean and tight?

If you have stator voltage into switchbox, and no spark out, either switchbox is bad or trigger or wiring are bad.

Thanks. I’ll check the ground on coils. But if I remember, each coil is individually grounded. All coils have no voltage.
Ill check the trigger again and also trace the wires To check them.
Thanks for the additional leads!

 

[BWR1953]

My new switchbox had the ground wire wadded up at the base. It would have been easy to overlook it amongst all those other wires. Might check to see if yours is fully grounded.

 

[Merccoper]

My new switchbox had the ground wire wadded up at the base. It would have been easy to overlook it amongst all those other wires. Might check to see if yours is fully grounded.

Thanks. Ya, my new switch box has that ground wire also. I attached it to the mounting bolt for the switch box, along with the other ground wires for the coil.

 

[Merccoper]

Thanks. I’ll check the ground on coils. But if I remember, each coil is individually grounded. All coils have no voltage.
Ill check the trigger again and also trace the wires To check them.
Thanks for the additional leads!

I checked the ground wires for the coil. Each coil has its own ground wire. Two are attached to the upper mount bolt and two to the lower mount bolt (mount bolt for the switch box). These are securely attached. Thanks again for the suggestion.

 

[Faztbullet]

What is voltage from stator?

 

[Merccoper]

What is voltage from stator?

It’s the black 16 amp stator for reference.
At cranking speed on a fully charged battery on low speed (blue wire) it is 245. High speed (red wire) it is 15. My rpm gauge isn’t working so I’m not certain of the rpms. Service manual calls for low speed 160-200 @ 300 rpms and 315-385 @ 1000 and 270-330 @ 4000. High speed is 8-10, 27-33 and 165-205.
I realize my readings don’t fall in the specific range but I assumed this was due to the rpms. Maybe this is my failing

 

[stresspoint]

the stopper switch i am addressing is on the motor , not the kill switch, it is to stop run on if the 2 stroke starts pre igniting / 2 stroking if the motor runs lean , that is what i think it does ,
guessing the mercury guys here will explain its purpose in more detail.

 

[Faztbullet]

the stopper switch i am addressing is on the motor , not the kill switch, it is to stop run on if the 2 stroke starts pre igniting / 2 stroking if the motor runs lean

No such thing on that motor...
ADI ignition is pretty simple,... cranking RPM generates AC voltage from stator, this is sent to switchbox where a internal rectifier converts to DC and stored in capacitor, trigger voltage off the hub magnet is sent to switchbox SCR to discharge the capacitor. Ohm your trigger coils and get a DVA reading off them.

 

[racerone]

Never hear of a " stopper switch "---That stops run on.

 

[Merccoper]

I’ve solved my problem from the below thread (sorry, not sure the best way to link the thread)

The solution is called a 2022 Suzuki 50hp. works like a charm now!!
(the bank is happy too!)

Still, still stuck with no spark

Hi all. I posted a thread about this last year and still struggling with it, so reaching out again for help. I’ve done additional test steps, but to summarize: On my second trip out on my new to me 1996 Mariner (see signature for detail) my engine just quit. No sputter, coughs or bangs...

forums.iboats.com

 

[alldodge]

Merged the threads