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  1. #1
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    Default Need Help with 82 shovelhead

    Hey guys,

    I've got an 82 shovelhead that I need some help with diagnosing why its acting the way it is. The bike has a dyna s ignition with the 5ohm dyna coil, and a Super B carb and is kick only. Typically a few primer kicks with the choke on and then will fire up on 1st or second kick. Idles fine and runs beautifully for about 30 to 40 miles and then it starts sputtering and missing. If I work the throttle I can usually keep it running long enough to find a spot to pull off before it dies. After that it will crank right back up on the first kick, will sit there and idle all day long. As soon as I pull back on on the road though I get the same thing usually less than 100 yards from where I was stopped. Bike starts spitting and missing and then dies.

    I really don't want to just throw money at it so I'm just looking for some ideas on what to start checking or if any of this is pointing towards a common failure. I've been through the carburetor and there doesn't seem to be any issue there. It seems like a component that is failing once it gets nice and warmed up. I know there are checks that can be done on coils and the dyna s ignition, that was my next plan. Just wanted to see what other advice you all might have. It also seems to be blowing a little white smoke out the pipes, makes me wonder if there is potentially a head gasket or top end issue?? Was planning on getting a compression test tool and seeing what kind of compression I have. Just not sure what to make of it running so well prior to it acting up, seems like if I had top end problems it would run rough all the time.

    Appreciate any help
    Attached Thumbnails Attached Thumbnails IMG_20201209_170208056.jpg  

  2. #2
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    Could be fouling a plug, I had an issue where the head gasket wasn't sealing good where the oil return runs through the cylinder and was dumping oil into the combustion chamber. I also had an issue where my regulator was failing and boiling off the acid in my battery. If you have a multimeter wouldn't hurt to see what voltage your charging at shouldn't be more than 13 or so volts I know mine was hitting 17 volts!

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    The symptoms could indicate a failing Dyna S, that's what they act like. Easiest diagnosis is to swap in a points set-up and see if the problem goes away.

    It could also be a fuel delivery problem, maybe no more complicated than a fuel cap with the vent blocked, or a fuel line deteriorating on the inside, or a petcock or petcock screen blocked with dirt or rust.

    Jim

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    I agree with JB Check the easiest and cheapest items first: IMHO

    Check in line fuel filer (If you have one)

    Check petcock screen

    Check to ensure you are chrging your battery while riding (Low or sporadic power can give off symptoms that mimic fuel starvation)

    About 30 miles of so on a system that isnt charging your battery is about how far you can get before symptoms show

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    Agree with JBinNC, Sound like your EI is failing or you fuel delivery is wacked. If it were me, when it starts to sputter, I'd run the bike with the fuel cap off, if it still sputtered, I'd look for collapsed or hot fuel lines, if that was all good, I'd swap the EI of points.
    Last edited by Fetch; 12-10-2020 at 12:12 PM.

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    You can check the electronic ignition with a hairdryer, that's my vote. If it shuts of quickly it's from heat at warmup and it's defective.

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    Thanks guys, lots of good feedback.

    I am definitely leaning towards replacing the ignition. I have just gone through the carb and its got a new petcock so I don't think fuel is the issue. I've tried unscrewing the gas cap and it doesn't seem to have any effect on it.

    This is what I was looking at if I were to go to points: https://www.denniskirk.com/drag-spec...prd/H42310.sku

    Would I also need a new coil? Or would the same 5ohm dyna coil work?

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    The points require a 5 ohm coil, the same as the Dyna S. You might consider another Dyna S, I think that is a good ignition. They seem to have about a 12 year life span, but some last considerably longer.

    Jim

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    Quote Originally Posted by JBinNC View Post
    The points require a 5 ohm coil, the same as the Dyna S. You might consider another Dyna S, I think that is a good ignition. They seem to have about a 12 year life span, but some last considerably longer.

    Jim
    Do you know what the difference is between the ds6-1 and the ds6k-1? Looks like the 6k just comes with a coil and the 6 doesn't? But the pictures look like the ignition itself is different.

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    The kit comes with a coil. If all you need is the pickup, the DS6-1 is what you need. But do the diagnosis first rather than throwing parts at it.

    Jim

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    Quote Originally Posted by Penguin74 View Post

    This is what I was looking at if I were to go to points: https://www.denniskirk.com/drag-spec...prd/H42310.sku
    Yes

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