Mercury Switch

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Chris1956

Supreme Mariner
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Disconnect the Mercury switch. It is on the front cowling support, and looks like a condenser from a magneto ignition system. Next disconnect the black/yellow wires at the switchboxes (there are two switchboxes. They may be on top of one another). Crank the motor and see if spark returns. If it does, you likely have a ground in your ign killler wire (black yellow), between the switchboxes and the ign key. You could also have a bad ign key.

Remember that ign system is an Alternator Discharge Ignition (ADI) system. It does not use any battery power to generate the spark. The black/yellow wires are grounded to kill the spark.
 
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Skeeter54

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May 28, 2015
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Gonna try it later today. Thanks for everyone's input. I wish there was somewhere I could find a process of elimination thread somewhere or at least a "go in this order" guide. If you all know of anything let me know. I don't wanna jump to something I don't have to if I can help it like mentioned earlier.
 
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Chris1956

Supreme Mariner
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Try the troubleshooting procedure on the CDIElectronics web site, for your ADI ignition,
 
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Skeeter54

Seaman
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Thanks Chris. Found some procedures online and researched some videos. We'll see what happens
 
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Skeeter54

Seaman
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So I tested all spark plugs today finally. Only getting fire on #3. I did also replace all plugs with new ones prior to that test. I also removed the stator and took it to a shop. Thankfully everything checked out. I then reinstalled everything and disconnected the black and yellow wires from the mercury switch to both power packs like you all and the shop mechanic said to but nothing. It did sound like it wanted to fire since I got a little exhaust pop here and there but i'm guessing that Im only getting fire on one plug is an issue? He also said to disconnect the main plug to the control box/ignition and jump the solenoid. If it started there then I can trace it back to the ignition/control box somewhere. Thoughts fellas? Thanks in advance.
 
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Chris1956

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You can ohm out your coils, but I doubt 5 of them are bad. Check the coil grounds.

Coil resistance on the primary winding is .02-.04 ohms (nearly a dead short). Resistance on the secondary winding to either + or - connections is 800 - 1100 ohms.
 
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Skeeter54

Seaman
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May 28, 2015
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That's what I was thinking. Okay I can check that. I need to check my trigger to count that out as well don't you think. From what I gathered at the shop for my 84 115hp I should get 100 ohms on it.
 
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Chris1956

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My service manual says 1100-1400 ohms for the trigger resistance test. The three pairs to test are: Brown (with sleeve) to white (without sleeve), White (w/o sleeve) to violet (with sleeve), and Violet (W/O sleeve) to Brown (with Sleeve).
 
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Skeeter54

Seaman
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May 28, 2015
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I found some specs for this motor. Said 800-1400 ohms? I landed right in the middle of these if that's right. Not second guessing your numbers just wanna make sure I'm good
 
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Skeeter54

Seaman
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May 28, 2015
Messages
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Also, mechanic told me to try and jump the solenoid while the harness is unplugged and see if it fires. If it does then harness issues I guess? Or what would be you alls next step?
 
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