1968 Johnson 40 HP no spark

Discussion in 'Outboards' started by turbowrenchhead, Sep 20, 2015.

  1. turbowrenchhead
    Joined: Sep 2015
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wisconsin

    turbowrenchhead New Member

    Good morning and hello. I'm a new member as of today. Thursday I picked up a 15' Fiberglass starcraft and a 1968 Johnson. The seller stated that the motor did not start and it probably needed a starter and or a solenoid. I am a mechanic so I checked out the motor to make sure it wasn't a dud. You can never trust what ppl tell you, that I have learned the hard way. So I brought some tools and a compression gauge. The compression was at 105psi on both. So that was a little low but live-able. Next I checked for spark and it had it. I shot a bit of starting fluid into the carb and it started for a couple seconds. So I bought it. I took it home and pulled the starter and solenoid and took it to a rebuild shop. They said nothing was wrong with the starter so they put it back together and sold me a solenoid and charged me $25. I put the starter and solenoid back on and now had a freshly charged battery. I cranked over the engine and I had no spark. I started looking it over and I came across a wire that was disconnected and I didn't remember disconnecting it from anything. After many hours of reading and downloading a manual I now know that it was the wire coming off the side of the cut out switch and is suppose to supply the ground to the starter solenoid. Before I knew what was what. I tried connecting it to ground and then to power and I still had no spark. No combination worked, still no spark.
    At this point I know that my safety switch is no good. Its always is a closed circuit. So that switch is bad. The previous owner must of had the safety switch and cut out switch bypassed because there is a wire going to the starter solenoid that has constant ground. After studying a wire diagram I tried hooking up power to the coils. Yeah the wire got warm fast. Thats not good! I pulled the flywheel and the RH side coil was warm. I ohmed checked that coil and I had .6 ohms on primary and 4000 on secondary. I would think that this is in spec but I have no parameters to go by.
    So my question is how do the coils get there power. Is there battery power supplied to both points and the points control the power side?
    I have two black wires coming out of the distributor but I don't know if they are suppose to both have power on them or not. Is white ground and black power?? Also I have no key. I have a series of toggle switches. Power, start, choke and lights.
    I'm a auto and atv mechanic however this is a whole new ball game for me. I'm used to stators and cdi's. Those I have no problem diagnosing. Did I fry my coils by supplying power to the distrib? Any help would be greatly appreciated. I thought I was going to be on the water today fishing with my family. That's not happening this weekend.
  2. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    The very first part you should by is the manual for this engine family. The easiest 30 bucks you give up.

  3. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 148, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    The coils do not get any power, they generate it from the changing magnetic field within the flywheel. Cut off or safety switches are normally open, when closed they bridge the breaker contacts to suppress the spark. 1968 technology!!
  4. turbowrenchhead
    Joined: Sep 2015
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wisconsin

    turbowrenchhead New Member

    I downloaded a manual from trade bit. The only thing useful in it was a wire diagram. However it did not state if black was ground or not. The wire coming off the cut off switch to the starter solenoid was a white wire in the diagram so there was a contradiction and made me question what black was.
    Is that manual any better. Does it have flow charts and specifications? The one I downloaded didn't have anything like a normal manual.

  5. turbowrenchhead
    Joined: Sep 2015
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wisconsin

    turbowrenchhead New Member

    I worked on my motor most of the day yesterday. All the distributor parts look newer. Unless this was stored in a climate controlled storage for its entire life. Not likely in Wisconsin. The coils have no cracks or signs of failure. I set the points today. I did not remove them. I resistance checked the points with everything disconnected. The resistance check should verify that they are working. One point set looks like the contacts are misaligned. There was no adjustment for alignment so I set the gap on both. However I still had no spark after all the resistance checks and point set.
    When I put it back together I just hit it with an impact at 90psi. I'll make sure to pull it tomorrow and re-torque it to 100-105 pds.
    I have to rewire this cobbled up mess of toggle switches. I should just get a ignition switch/key and redo it right. Anyone know a of a cheap one that would work for me? It doesn't have to be OEM. Any good aftermarket will do.
    In my research today I found that my motor is a 1969 model year and not 68 like it states on the registration card. I do believe that the wire diagrams were any different for the ignition system from 68 to 69. I have a 40E69R model.
    I had yet another issue with this pain in my ***. The shifter cable is seized up. I lucked out and found a new shifter cable for $35 shipped to my door. I seen that most were going from 89-129. Yikes!
    Hopefully by next weekend I'll be able to get this vintage ride on the water by next weekend. The fish are starting to bite now after the heat has died off. I'm getting antsy to go fishing!
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