RemingtonHoliday
Recruit
- Joined
- Aug 28, 2025
- Messages
- 2
Hi all. Hoping to get some input on the problems I'm having with my 1984 Mercury 90 hp inline 6, with ADI.
Last year I had a problem where I couldn't get it to start unless I sprayed premix into the carbs, and then it would run, but basically couldn't get it above an idle.
I found that there wasn't spark on all cylinders, and I can't remember which ones. I did some testing and found that the Blue wire was bad on the stator. The trigger tested normal. So I ordered a CDI stator and then didn't get to work on it again until just recently.
I replaced the stator, and rebuilt the entire fuel system. Put everything back together, and now I don't seem to have ANY spark on ANY cylinder. I retested the new stator, and the trigger, which are all within DVA specs. One thing I did notice was when I tested the trigger with wires not connected to the switch box they were 4+ volts, but when I tested the same with the wires connected to the switch box, the voltage dropped to between 2 and 3 volts. I am not sure if this is a valid test with the wires connected to the switch box, or if it is any indication that the switch box is bad?
I find it strange that I have now lost all cylinders, and was wondering about the switch boxes, but I also find it strange that I'd lose all spark and both boxes are bad now.
Can anyone suggest any different testing I could do? I am going to try testing the coils.
Is there anything such as a wire or something that I could have loosened/disconnected by accident at the front of the motor when I had it apart for the carbs? That could have caused a no spark condition? I did try with the kill switch wire removed, and with the yellow rectifier wires removed. I had the big 7 pin connector apart and I cleaned it all up and applied dielectric grease, but I didn't think there was anything in there that would affect the spark, aside from the kill switch.
Do you usually test the trigger, stator, coils with them connected to the switch boxes? or disconnected?
Thanks for your time!
Last year I had a problem where I couldn't get it to start unless I sprayed premix into the carbs, and then it would run, but basically couldn't get it above an idle.
I found that there wasn't spark on all cylinders, and I can't remember which ones. I did some testing and found that the Blue wire was bad on the stator. The trigger tested normal. So I ordered a CDI stator and then didn't get to work on it again until just recently.
I replaced the stator, and rebuilt the entire fuel system. Put everything back together, and now I don't seem to have ANY spark on ANY cylinder. I retested the new stator, and the trigger, which are all within DVA specs. One thing I did notice was when I tested the trigger with wires not connected to the switch box they were 4+ volts, but when I tested the same with the wires connected to the switch box, the voltage dropped to between 2 and 3 volts. I am not sure if this is a valid test with the wires connected to the switch box, or if it is any indication that the switch box is bad?
I find it strange that I have now lost all cylinders, and was wondering about the switch boxes, but I also find it strange that I'd lose all spark and both boxes are bad now.
Can anyone suggest any different testing I could do? I am going to try testing the coils.
Is there anything such as a wire or something that I could have loosened/disconnected by accident at the front of the motor when I had it apart for the carbs? That could have caused a no spark condition? I did try with the kill switch wire removed, and with the yellow rectifier wires removed. I had the big 7 pin connector apart and I cleaned it all up and applied dielectric grease, but I didn't think there was anything in there that would affect the spark, aside from the kill switch.
Do you usually test the trigger, stator, coils with them connected to the switch boxes? or disconnected?
Thanks for your time!