No spark. Boyer brandsen ignition. How to test?

Discussion in 'Airheads' started by henrybayuzick, Sep 16, 2013.

  1. henrybayuzick

    henrybayuzick Adventurer

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    Hey everyone,

    I've got a 78 R60/7 that's dual plugged. Recently I tore it down to make some modifications to it, and in the process I rewired it from scratch using the M-Unit.

    When I purchased the bike, it had a Boyer Brandsen electronic ignition setup, with 2 red Dyna coils. All of that wiring I kept in place. So currently it is ignition switch start -> starter relay -> starter and all other functions.

    Here's the problem: no spark. Being my first build, I'm looking for some guidance on how to test where the problem lies. I'd like to determine if it is an error on my part (wired incorrectly) or if it's the ignition unit, coils, etc failing. The bike did run before I tore it down and I've retraced through several diagrams and everything looks correct.

    Where should I start and what kind of resources/images can I provide this community to help better understand my problem so you are able to put me in the right direction? I appreciate the time.

    Thanks.
    #1
  2. Stan_R80/7

    Stan_R80/7 Beastly Gnarly

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    Here is a link to the instructions for installing a Boyer-Brandsen igntion. It sounds like you have either the MKIII (KIT00098 (BOX00024)) or micropower (KIT00286 (BOX00237)) ignition for the pre '79 2V Boxers. I expect an email to their technical support may be useful for a specific (technical) question. Reading and following the instructions for installation should help. Good luck!


    Edit: the micropower uses specific coils and is the most modern unit, so it is unlikely that is what you have, the micro digital (KIT00086 (BOX00037)) uses standard or red dyna coils. So the most likely suspects for what Boyer unit you have are the MKIII and the micro digital. The MKIII has only one black wire to the stator.
    #2
  3. henrybayuzick

    henrybayuzick Adventurer

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    Thanks for the resources. I studied those all day yesterday and it seems as if all is correctly connected. The only one I can't completely confirm is how it is hooked to the stator. Anybody have pictures of how theirs is? The unit was installed before I bought the bike.

    If all is connected correctly, what would be the next step? How could I test each part of the setup for failure?
    #3
  4. bmwrench

    bmwrench Long timer

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    IIRC, "scratching" the stator leads together is supposed to cause the black box to trigger the coils.
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  5. pommie john

    pommie john Long timer

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    What kind of Boyer? Analogue or digital?

    With the old analogue Boyer you should get a spark when you switch off the ignition.
    #5
  6. pommie john

    pommie john Long timer

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    It's just one wire going into the beancan. It is earthed ( grounded) through the beancan body. Make sure that the little screws that hold the stator plate into the beancan are clean and corrosion free because they are your earth connection.

    That's for the analogue Boyer. It may be the same for the digital but I don't know.


    I have soldered an earth onto the stator plate of mine which connects through the ring terminal you can see in this shot. I did that because it got a poor earth on those little screws when they got corroded.

    [​IMG]
    #6
  7. Rob Farmer

    Rob Farmer Long timer

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    If it has one wire then it's probably an early unit. Is it a black control box?

    They make a micro digital unit with a twin plug curve that would be a much better solution, those early units have a poor curve that doesn't suit anything
    #7
  8. henrybayuzick

    henrybayuzick Adventurer

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    Thanks for all the replies. I forgot to specify the box. It's box00024 or the mkIII. It's the electronic ignition. I'll take pictures of each part of the system once I get home for everyone to look over.

    I'm wondering if there is no spark due to the ignition box failure or if its something else that is wrong. I'm just not sure how to go down the line and test each part for success.

    bmwrench: mind expanding on your reply a bit more? It looks like I have one black wire that goes through a tube, and then is soughered to the stator. Maybe I'm missing something all together.

    Thanks again for the replies.
    #8
  9. pommie john

    pommie john Long timer

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    OK it's an analogue Boyer.

    You should get a spark when you turn the ignition off.

    If you don't, disconnect the stator wire and try again. If you now get a spark you've got a stator problem.

    From memory there should be around 120 ohms across the stator pick-up coils. That is, you disconnect the stator wire and put one lead of a multimeter on that, and one lead on ground. There should be around 120 ohms.
    #9
  10. Plaka

    Plaka Brevis illi vita est

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    On the early boyers there was an issue with corrosion on the back of the stator board. You got a poor ground connection and it wouldn't work. Supposedly improved on later models. But it wouldn't hurt to pull the stator and look on the back as well as clean up the block behind it.
    #10
  11. Rob Farmer

    Rob Farmer Long timer

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    #11
  12. henrybayuzick

    henrybayuzick Adventurer

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    Thanks for tips. I'll try these this weekend. Rob Farmer, what ignition do you recommend? I don't mind buying a new one.
    #12
  13. regomodo

    regomodo Been here awhile

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    What's the later unit? I have the mk3 and can't say I like it; very tacky looking, poor build, and bike runs like crap with full-advance @3500rpm. It's also a pain to start the bike with it in the cold. I had to back off the timing to stop it pinging.
    #13
  14. pommie john

    pommie john Long timer

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    Time it at 5000rpm. It keeps advancing until at least 5000.
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  15. regomodo

    regomodo Been here awhile

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    Ah right. The guide says ~3500 and the first time I went out the bike lugged nicely but wouldn't rev out (pinging). I took some allen keys, went to a quiet industrial estate and backed off the timing until it stopped pinging. I'll see where I've ended up sometime (my garage is surrounded by houses and my bike is loud). It runs fine now, just starting the bike is an issue sometimes. It was push & go when I had points on, even in sub-zero temps.
    #15
  16. Rob Farmer

    Rob Farmer Long timer

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    The black box units are just a linear advance that doesn't seem to suit anything. The micro power units are sweet with a curve that suits the airheads a treat.

    I agree with the comments about the control box. They are a pain the arse to mount properly.
    #16
  17. chasbmw

    chasbmw Long timer

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    Your rev counter is not always the best tool to time a Boyer. Set it on the F mark when you see it stops advancing. Even with standard pipes it's quite a noisey process.
    #17
  18. rheritage

    rheritage Been here awhile

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    My 72 R75 has a Boyer, the control box has an inline fuse, not sure if yours does but worth a quick check, you never know.

    Good Luck,
    Rich
    #18
  19. henrybayuzick

    henrybayuzick Adventurer

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    As I was working through this today, my starter got jammed and it looks like I'll be ordering a new one. The bike has 68k miles, so I guess it is time.

    In the meantime, would anyone mind explaining the process for spark and possibly recommend an optimal ignition setup for a dual plugged system? I'm considering starting fresh. Before my starter got jammed, I was starting to think that maybe I had hooked the coils up incorrectly. I assume they are supposed to be wired in parallels, but I don't know a thing about ohms, etc. I think my lack of knowledge is hindering me from finding the cause behind no spark.

    I don't really understand advance, curve, etc relative to ignition, and what electronic ignition eliminates, and how a dual plugged system affects the above. I just want the best setup.

    So a recap: I've currently got a boyer brandsen mk3 electronic ignition (black box) and two red dyna coils, I couldn't find the exact pair I have anywhere online. No spark, despite going through various diagrams, cleaning the stator, "scratching" the leads, etc. However, I wasn't able to power a light bulb from the starter relay wire that would normally go to the electronic ignition... so there may be a problem there.

    I appreciate all the wisdom. I've got quite a bit of learning to do. :ear
    #19
  20. pommie john

    pommie john Long timer

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    If you mean the brown Dyna coils ( they're a sort of browny/orangy/red colour) they should be wired in series. They are 1.5 ohms and you need around 3 ohms for the Boyer. This means all the spark plugs fire at once every time a piston reaches TDC ( actually just before TDC, but you get the picture).
    #20