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Thread: Problem with S & S Super E "Shorty" Carburetor on '67 FLH

  1. #21
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    Quote Originally Posted by jamesgraulty View Post
    Good advice, and I've done just that. In this order: new condenser-no fix; new points-no fix; new plug wires-no fix; new coil-no fix. And I've examined all the wiring I can see at both the timer end and coil end and it appears in good order. I put new plugs in after the carburetor rebuild. The only time on them was the very short runs after each of the new ignition parts was installed, to determine if the problem still existed. I looked at them a few times. The front seemed to carbon up a bit, but cleaned up easily, and the rear was always clean. So today after the new coil went in I decided to pull plug wires while it was running to see what would happen. Mind you it was still popping and missing real bad. The excess gas would drip out over the backplate and you could see the flash behind the throttle plate each time it popped. When I pulled the front cylinder plug wire off the popping stopped and it actually ran smoothly on the rear cylinder. Put the front wire back on and the popping started. Then pulled the rear wire and it stopped running. So something is up with the firing of the front cylinder, for which I haven't a clue. And I switched the plugs to see if it was a bad plug. Did the same thing. Popping and spurting, but pull the front wire off and runs smooth, on just the rear cylinder. I don't know what else to do??
    Is the intake valve on the front cylinder closing completely at each compression before firing?
    AFJ

  2. #22
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    Oct 2012
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    Quote Originally Posted by AFJ View Post
    Is the intake valve on the front cylinder closing completely at each compression before firing?
    AFJ
    I don't know but I was starting to think along those lines. I had noticed what I thought was a progressively worsening valve train noisiness right before the problem started and was planning to check tappet adjustment, until I got sidetracked on thinking it was carburetor and then ignition. Now that I think I've ruled both of those out I'm going to get into that next. Maybe that will tell me something. Could a bad lifter cause that?

  3. #23
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    Quote Originally Posted by jamesgraulty View Post
    Good advice, and I've done just that. In this order: new condenser-no fix; new points-no fix; new plug wires-no fix; new coil-no fix. And I've examined all the wiring I can see at both the timer end and coil end and it appears in good order. I put new plugs in after the carburetor rebuild. The only time on them was the very short runs after each of the new ignition parts was installed, to determine if the problem still existed. I looked at them a few times. The front seemed to carbon up a bit, but cleaned up easily, and the rear was always clean. So today after the new coil went in I decided to pull plug wires while it was running to see what would happen. Mind you it was still popping and missing real bad. The excess gas would drip out over the backplate and you could see the flash behind the throttle plate each time it popped. When I pulled the front cylinder plug wire off the popping stopped and it actually ran smoothly on the rear cylinder. Put the front wire back on and the popping started. Then pulled the rear wire and it stopped running. So something is up with the firing of the front cylinder, for which I haven't a clue. And I switched the plugs to see if it was a bad plug. Did the same thing. Popping and spurting, but pull the front wire off and runs smooth, on just the rear cylinder. I don't know what else to do??
    You've got all the clues you need, James.

    Are you fearful of a bubble-test?

    ....Cotten
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  4. #24

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    Cotton is right.Either bad intake leak or no fire on the front cylinder.Did you put a timing light on the front cylinder & watch to see if there is spark ? If it has spark it is most likely an intake leak.

  5. #25
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    Quote Originally Posted by duffeycycles View Post
    Cotton is right.Either bad intake leak or no fire on the front cylinder.Did you put a timing light on the front cylinder & watch to see if there is spark ? If it has spark it is most likely an intake leak.
    It's nearly always an evil manifold leak, Folks!

    But other things could be amiss,.. too.

    (Never does only one thing go wrong at a time.)

    ....Cotten
    Last edited by T. Cotten; 07-11-2018 at 12:27 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  6. #26
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    Quote Originally Posted by duffeycycles View Post
    Cotton is right.Either bad intake leak or no fire on the front cylinder.Did you put a timing light on the front cylinder & watch to see if there is spark ? If it has spark it is most likely an intake leak.
    Thanks again for the input folks. So I checked and the front cylinder has spark. I was pretty sure it always did but I visually jumped the plug wire to the end of the plug to see the spark. Then I tried spraying Wd 40 all around the intake ports and where the carb attaches to the manifold while it was running. No effect on anything. I don't have the stuff to do a bubble test. So I put in new manifold O-rings. This S & S set up uses just the O-rings and the metal band to attach the intake manifold. Carefully inspected manifold and ports while apart and could not detect any flaws. Made sure everything was real clean and lined up good going back together. Still does the same popping, and stops when I pull the front plug wire off, like before. Sprayed around everything after the new manifold O-rings went in. No effect. So assuming I've ruled out intake manifold leak, what's left? All I can think of now is it's valve related. Maybe a broken valve spring? Or something else in the valve train? Stumped again.

  7. #27
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    Quote Originally Posted by jamesgraulty View Post
    Thanks again for the input folks. So I checked and the front cylinder has spark. I was pretty sure it always did but I visually jumped the plug wire to the end of the plug to see the spark. Then I tried spraying Wd 40 all around the intake ports and where the carb attaches to the manifold while it was running. No effect on anything. I don't have the stuff to do a bubble test. So I put in new manifold O-rings. This S & S set up uses just the O-rings and the metal band to attach the intake manifold. Carefully inspected manifold and ports while apart and could not detect any flaws. Made sure everything was real clean and lined up good going back together. Still does the same popping, and stops when I pull the front plug wire off, like before. Sprayed around everything after the new manifold O-rings went in. No effect. So assuming I've ruled out intake manifold leak, what's left? All I can think of now is it's valve related. Maybe a broken valve spring? Or something else in the valve train? Stumped again.
    Check/Adjust Front cylinder intake valve tappet adjustment?
    AFJ

  8. #28
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    Quote Originally Posted by AFJ View Post
    Check/Adjust Front cylinder intake valve tappet adjustment?
    AFJ
    That will be my next step. I had been planning on doing all the tappets when this problem started. I thought they were getting noisy when this problem started.

  9. #29
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    Quote Originally Posted by jamesgraulty View Post
    ... Sprayed around everything after the new manifold O-rings went in. No effect. So assuming I've ruled out intake manifold leak, what's left? ...
    No James.

    You have not ruled out a vacuum leak at all.

    ....Cotten
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  10. #30
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    Well I'm happy to report I've solved the problem. Remember when I said I thought the valve train clatter was getting progressively worse during the ride when this problem hit. Today when I took the front exhaust push rod cover off the push rod fell right out. And the lock nut was loose. I determined I have solid lifters, instead of the stock hydraulics. I adjusted all the push rods. It fired right up and is purring like a kitten. I've learned a lot from this experience. And the carburetor and ignition work and manifold o-rings isn't wasted. I've learned from it and know where these key items stand now. Thanks to all who replied to this thread. The input is very valuable, for now, and in the future. Thanks again!

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