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1947 Flathead Ford - no spark. Common issues?

Discussion in 'The Hokey Ass Message Board' started by TimberwolfFXDL, Jul 27, 2012.

  1. TimberwolfFXDL
    Joined: Jul 15, 2012
    Posts: 44

    TimberwolfFXDL
    Member

    Let me preface this by saying I don't know much about the project to date. I received a message from a friend asking if I knew anyone knowledgeable in the flatheads motors.

    He picked up a 47 Ford pretty cheap, but was told the motor was seized. Turns out that it wasn't. Some of the accessories were stuck, but not seized. We pulled the plugs, put a little mystery oil in each cylinder, turned the motor over by hand a couple times, and then let it sit until the newly ordered plug wires and such came in. That's the last I touched it.

    He's swapped in the new wires, fixed up the wiring, checked it all over with the multimeter, and everything seems legit based on what he can find online....except he's getting no spark.

    Are there common issues to look for? I'm not at all familiar with 6V positive ground systems, nor with the flathead's ignition system. So I can't help at all.

    Any help is appreciated!
     
  2. 4t7flat
    Joined: Apr 15, 2009
    Posts: 266

    4t7flat
    Member

    On old flatheads,that have not run in many years,it's usually the condenser that needs replacing.
     
  3. TimberwolfFXDL
    Joined: Jul 15, 2012
    Posts: 44

    TimberwolfFXDL
    Member

    Thanks for the tip! Anything else to look for?
     
  4. check for voltage at one end of the coil with the key on,and a blinking light on the other end to the dist with the engine turning over.might help narrow down some issues.
     

  5. gallagher
    Joined: Jun 25, 2006
    Posts: 189

    gallagher
    Member
    from califorina

    replace condenser
     
  6. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    JohnEvans
    Member
    from Phoenix AZ

    Clean or replace the points,and make sure they are gaped right and opening /closing.
     
  7. TimberwolfFXDL
    Joined: Jul 15, 2012
    Posts: 44

    TimberwolfFXDL
    Member

    I swung by there today. He said he had checked everything out with the ohm meter and has continuity in all the right places.

    So on a hunch, I used the ohm meter and checked for continuity in all the wrong places. Guess what...

    Somewhere he has a dead short. EVERTYTHING has continuity as far as power and ground wires go. Hell, even the positive and negative battery cables (not hooked to the battery) showed zero resistance between them.

    I told him to pull the generator and ignition wires off the solenoid and run direct power to the coil. Then we dug out his remote start switch and I showed him where to hook it up to the solenoid. Tomorrow he'll test things that way and see if it makes a difference. He already replaced the coil, solenoid, condensor, points (and made sure they are operating), plug wires, plugs, etc.

    There's not much else that could be wrong other than a dead short at this point, and my suspicions were confirmed with the ohm meter.
     
  8. 49ratfink
    Joined: Feb 8, 2004
    Posts: 18,828

    49ratfink
    Member
    from California

    did you check for volts anywhere?

    something I just learned from here while working on a flathead. my solinoid has a button on the bottom you push that will turn the motor over, no need for a remote starter.
     
  9. Old Dude
    Joined: May 12, 2006
    Posts: 193

    Old Dude
    Member

    I had a '47 Ford, with a 52 V/8 Flatty in it. A couple of times it shorted out, and quit. I found the problem by pulling out Distributer, and the wire leading to condsor was bad. Replaced it with new wire, and fired right up, and never did have any trouble after that ! Cruise On
    Old Dude
     
  10. TimberwolfFXDL
    Joined: Jul 15, 2012
    Posts: 44

    TimberwolfFXDL
    Member

    thanks for the tip! I passed it on, and he pulled the distributor. Found the brass stud to the condensor was shorting internally. I wasn't there, so I don't know much about the details, but I guess he has a new distributor on the way. Hopefully it solves the problem!
     
  11. 40FordGuy
    Joined: Mar 24, 2008
    Posts: 2,907

    40FordGuy
    Member

    Another common issue is the ign coil,.... If you still have the original, it can be bad. Those Fords had a ballast resistor mounted right on the coil batt terminal,...check that,...; If it's not there, running full battery voltage can kill the coil. <I learned that the hard way>

    4TTRUK
     

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