92 Mercury 25hp 2-stroke - Not getting spark

RoyalCrest

Recruit
Joined
Jun 27, 2022
Messages
4
Hi folks... first-time boat owner and I would love some help. We have a 92 Mercury 25hp 2-stroke and the spark plugs are not getting any spark. The kill switch is off and in working condition - we tested it. We replaced the spark plugs, ignition, coils, stator, motor fuse, and CDI box. Seems there is still no power to the coils. What are we missing??? I just ordered a trigger... maybe it's that???? Please help.
 

btclark0316

Cadet
Joined
Jun 26, 2022
Messages
9
Have you checked and secured all grounds on ignition system? So the plugs are not getting any spark at all, or is it weak/intermittent spark?
 

RoyalCrest

Recruit
Joined
Jun 27, 2022
Messages
4
Yes, they are secure but I will double-check again tomorrow.
Plugs arent getting any spark what-so-ever.

We ran the boat once for about 2 hours then docked it. Came back the next day and ran it for about 30 mins before we anchored so kids could jump off and swim. Restarted it and it stalled out about 30 seconds later. We towed it back to the dock and checked the spark plugs and they were dirty/gunky - we were able to get it started one more time while at the dock - we shut it down and it hasn't run since. We replaced the plugs because we thought they were likely the reason why it stalled. Since the new plugs didnt start the motor, as expected... we moved on the replace the coils, ignition, fuse, stator and tonight we replaced the CDI box.
 

btclark0316

Cadet
Joined
Jun 26, 2022
Messages
9
Yes, they are secure but I will double-check again tomorrow.
Plugs arent getting any spark what-so-ever.

We ran the boat once for about 2 hours then docked it. Came back the next day and ran it for about 30 mins before we anchored so kids could jump off and swim. Restarted it and it stalled out about 30 seconds later. We towed it back to the dock and checked the spark plugs and they were dirty/gunky - we were able to get it started one more time while at the dock - we shut it down and it hasn't run since. We replaced the plugs because we thought they were likely the reason why it stalled. Since the new plugs didnt start the motor, as expected... we moved on the replace the coils, ignition, fuse, stator and tonight we replaced the CDI box.
Yes, they are secure but I will double-check again tomorrow.
Plugs arent getting any spark what-so-ever.

We ran the boat once for about 2 hours then docked it. Came back the next day and ran it for about 30 mins before we anchored so kids could jump off and swim. Restarted it and it stalled out about 30 seconds later. We towed it back to the dock and checked the spark plugs and they were dirty/gunky - we were able to get it started one more time while at the dock - we shut it down and it hasn't run since. We replaced the plugs because we thought they were likely the reason why it stalled. Since the new plugs didnt start the motor, as expected... we moved on the replace the coils, ignition, fuse, stator and tonight we replaced the CDI box.
Have you checked and secured all grounds on ignition system? So the plugs are not getting any spark at all, or is it weak/intermittent spark?
 

btclark0316

Cadet
Joined
Jun 26, 2022
Messages
9
Okay, do you have a DVA adapter to check and troubleshoot components? Also are you positive it is not getting any fire, like did you try to crank motor with pulled plug and look for spark? I pulled a copy of a mercury 25 HP repair manual and will attach its ignition troubleshooting page.
 

btclark0316

Cadet
Joined
Jun 26, 2022
Messages
9
Okay, do you have a DVA adapter to check and troubleshoot components? Also are you positive it is not getting any fire, like did you try to crank motor with pulled plug and look for spark? I pulled a copy of a mercury 25 HP repair manual and will attach its ignition troubleshooting page.
2D579F15-6BBE-4B5E-AAEC-7CB13D6921D2.png
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,095
Is this a tiller or remote model? Electric or manual start? Is the toggle kill switch it the correct position?? Try Disconnecting the black wire/yellow stripe from the CDI box. How have you checked spark? What is your compression?
 

RoyalCrest

Recruit
Joined
Jun 27, 2022
Messages
4
Is this a tiller or remote model? Electric or manual start? Is the toggle kill switch it the correct position?? Try Disconnecting the black wire/yellow stripe from the CDI box. How have you checked spark? What is your compression?
Ok.... disconnected black and yellow and still not starting. Not sure of compression.... i don't have that tool at the moment - hubby will bring it after work. What is the peach colored wire not connected to anything?
 

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RoyalCrest

Recruit
Joined
Jun 27, 2022
Messages
4
Ok.... disconnected black and yellow and still not starting. Not sure of compression.... i don't have that tool at the moment - hubby will bring it after work. What is the peach colored wire not connected to anything?
Technician that came yesterday confirmed there was no spark and said the coils are not getting power. I'm here today making sure all the ground wires are secure.
 
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