35hp Mercury with no spark-Revisited

Discussion in 'Bubba's Outboards' started by Raven Blayde, Dec 27, 2009.

  1. Raven Blayde

    Raven Blayde New Member

    Messages:
    320
    State:
    Kentucky
    I'm still at it everyone! 68' 35hp Mercury Twin 350 still has no spark on the #2 cylinder, but the motor runs on the #1. So far, I've replaced the points, checked gap, condensor, replaced the ignition coil, tried 3 different sparkplugs and nothing! I'm going back and questioning the hookup of the new coil and sparkplug wire. The ignition coil only has a small pin inside of the hole where the sparkplug wire is inserted. The sparkplug wire itself is bare on the end and has no connector at all on it. I was assuming that when the bare plug wire was pushed into the ignition coil hole, the small pin that's inside would go up the middle of the bare sparkplug wire-Giving it it's connection. I might be wrong here. Was this plug wire suposed to have some sort of connector on it? Thanks in advance
     
  2. Raven Blayde

    Raven Blayde New Member

    Messages:
    320
    State:
    Kentucky
    After much research, I've discovered that my sparkplug wire to coil connection is in fact correct. I'm now going through my electrical wiring and finding a few things that have me confused. On the side of the motor, there is a junction block with 5 screws from what I remember. The first and last screws hold the junction block to the motor, so they would be "grounds" and not used. That leaves 3 useable connections on the block. The first 2 wires go to the coils and points. One wire is "Hot" and one is "Not" when I have the key on. The 3rd wire on the harness goes to the 3rd spot on the junction block and is by itself (doesn't connect to anything else). I'm really questioning those first 2 wires (that run to the coils and points). Should it be one "Hot" and one "Not", or should both coil/point wires be "Hot" when the key is on? If they should be, then I've tracked it down to either the harness plug or the key switch. I can unplug the main harness (the boat end) and turn the key on. Using the light tester (only thing I have right now) in the harness holes, I have good light going to the starter solinoid, main battery cable and only one of the igniton coils/points. The other coil and the wire that is by itself on the junction block are either dim or non existant. I've been all over the net for 3 days now trying to find some sort of wiring diagrams for this motor so I can see for myself what wires should be where and what should be correctly "Lighting Up". So far, no luck. Any suggestions?
     

  3. catwhisper

    catwhisper New Member

    Messages:
    456
    State:
    georgia
    have you messaged Bubbakat or Bob Paul? i'm sure they can help
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Put the serial number on here and I'll see what I can come up with.
     
  5. Raven Blayde

    Raven Blayde New Member

    Messages:
    320
    State:
    Kentucky
    Thanks! Serial number is 2301754
     
  6. Raven Blayde

    Raven Blayde New Member

    Messages:
    320
    State:
    Kentucky
    I just got a Mercury Repair Manual for my motor. It's a big (and expensive) manual that covers anything and everything. So far, I've learned that what I have is called a "Type 1" ignition system and if I'm reading this correctly, I should be able to unhook the wiring harness completely and run the motor without it by using the pull rope to start it. If this is so, and the 2 cylinders fire without the harness, that will tell me if it's a problem with the wiring harness. Is that right? I'm just curious to know because it will probably be a while before I atempt to fire it (it's in the teens outside).
     
  7. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    All that will do is tell you if the ing switch is bad or not. I'll get on mine tonight and help you with this. I have been totaly lazy these last few cold days.
     
  8. Raven Blayde

    Raven Blayde New Member

    Messages:
    320
    State:
    Kentucky
    Finally, made some serious progress today (which really suprised me) lol... as you guys know, I've been all over this motor and nothing seemed to fix the problem of no spark on the #2 plug. Before, I could unplug the #2 plug wire with the motor running and it made no difference. If I unplugged #1 and left #2 plugged in, the motor would die on the spot. Well, today I tried unplugging the whole wiring harness and pull starting the motor. It fired up after several pulls, but ran TERRIBLE!!! It smoked me out of the garage and was missing real bad. I shut it down and checked the sparkplug. Now, BOTH sparkplugs were soaked with fuel. For the heck of it, I decided to make some adjustments to the timing and the throttle (give it more timing and less fuel). It ran better, but still smoking and missing. While it was running, I pulled the #2 plug wire- It ran worse. Finally, I saw a difference without #2 hooked up. I put it back and pulled #1- Still ran, but died after about 10 seconds. At least I knew #2 was now firing. Tried advancing it a bit more- Ran MUCH better!! Engine didn't smoke anymore (except the normal from the oil/fuel mix) and just barely had a slight miss to it at idle. Hit the throttle and the motor instantly RPM's like a dragster!! lol... YES!!! Progress!!! I then grabbed the #2 plug wire to pull it and see what happens- As I pulled it off, it shocked the crap out of me (which was really fun since I was running the motor with muffs and standing in the running water). lol.... I have spark!!! Just wanted to update.
     
  9. Trapper-steve

    Trapper-steve Well-Known Member

    Messages:
    1,102
    State:
    Bicknell, IN
    Sounds like you are getting there :pray:
     
    Last edited: Jan 27, 2010