Custom ignition or programmable

Discussion in '2 smokers' started by greasyfatman, Feb 14, 2020.

  1. greasyfatman

    greasyfatman Long timer

    Joined:
    Oct 18, 2014
    Oddometer:
    3,327
    Looking for people's experiences with custom ignitions or programmable ignitions.

    I may try and adapt some zeeltronic stuff to 80cc motor I will be working on.

    Any thoughts please share.
    #1
  2. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    I adapted Pertronix ignition modules to my 73 Harley Sprint and 76 Yamaha RD400. It took some machine work but they run great. I am going to come up with a system for my 73 Suzuki TC100, maybe components from a chainsaw, weedwhacker or something like that.
    #2
    spokester likes this.
  3. greasyfatman

    greasyfatman Long timer

    Joined:
    Oct 18, 2014
    Oddometer:
    3,327
    Neat. Just looked them up. I think I will need to go from a pickup inside the fly wheel to an external pickup for zeeltronic.

    What did you have to mechine?
    #3
  4. snarlyjohn

    snarlyjohn Human money repellant

    Joined:
    Apr 1, 2016
    Oddometer:
    469
    Location:
    Australia
    What engine? There are lots of options, but whatever you choose I'd go for a CDI, even if it's only for its better ability to fire a fouled plug. Another thing to do whether it's a fixed or programmable advance is to check the timing with a strobe over the entire rev range - almost all magnetically triggered systems have some amount of latency built in that gives some progressive retard with rpms. Not necessarily a bad thing but you need to compensate for it. A popular choice with many builders is the Chinese GY6 flywheel and stator - it's cheap, reliable and works well with most aftermarket CD boxes.
    #4
  5. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    Bases and mounts, the tricky part on the Sprint was marrying the magnet ring to the centrifugal advance mechanism. I timed it with a light and it started right up. The RD has no advance but was tricky to get them exactly 180 degrees opposite on the baseplate so i made a little jig to get real close then adjusted each slightly by static timing with my homemade gutted spark plug TDC tool.
    #5
    greasyfatman likes this.
  6. greasyfatman

    greasyfatman Long timer

    Joined:
    Oct 18, 2014
    Oddometer:
    3,327
    I have mapped and made changes to the KDX CDI. I am an Electrical Eng from the analog days. I think I want to go digital for quicker adaptability. So I can see what changes have what affect.

    I am working with a BW80 two stroke motor now. Just rebuilding the ignition with 1% resistors and caps, components that are not 30 years old would make a difference. Thought about having some switch able resistance to change discharge time.


    But digital gives me a lot more control and I can geek out.
    #6
    Pezz_gs likes this.
  7. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    I have no geek credentials but am a pretty creative jack of all trades
    #7
    greasyfatman likes this.
  8. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    Seems I have the time now so I will attempt to adapt a 96 Suzuki DS80 system to the old 73 TC100. Parts are coming, it looks like the fly wheel hub will need swapped and it will need a rec/reg to charge the battery. I love the old bikes but points are a drag or at least rusty points cams are!
    #8
  9. greasyfatman

    greasyfatman Long timer

    Joined:
    Oct 18, 2014
    Oddometer:
    3,327
    Thanks a lot for the come back on this. I am looking at yz80 wheel and pick up and zeeltronics ignition. I have resized and printed a degree wheel.

    I am interested in what you figure out. Post pics or discoveries if you can.
    #9
  10. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    I am gaining on it, first up was to capture the BTDC measurements with the original points set at 012 and again at 016, then I ground off the rivets holding both flywheels to the hubs, luckily the hub ODs were the same and 4 of the six rivet holes match, nice break! More to come...
    #10
  11. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    The newly configured flywheel has a little less height available under it than what I needed and I noticed the lighting coil sits on a couple of raised posts relative to how the ignitor coil sits so I lowered the posts with my mill to get enough clearance (about .100). I hope I don't come to regret that! I also had to clean all the conflicting casting parts off both base plates so I could tightly stack the new DS80 plate on the original TC100 plate and screw them together in a way that will allow the timing to be adjustable. I put it together and found that the flywheel skirt was rubbing on said screws so I pulled the flywheel and shaved .025 off the skirt in the lathe. Replacing the rivets came down to drilling out the original 5mm holes to .250 and using grade 8 1/4 x 1/2 nuts and bolts but the bolt heads were a little thick and threatened to rub on the lighting coil so I shaved them down some on the lathe to about .085 thick and that seems about right. I timed it as best I could with my youngest son kicking it over with me on the timing light, I had to redrill and tap to move the screws a couple times but finally got it in the ballpark. Put some gas to the carb and three kicks and it started, sounded good but he timing light says it is a little too advanced. Enough for tonight maybe more tomorrow.
    #11
    greasyfatman likes this.
  12. 380Viking

    380Viking Adventurer

    Joined:
    Apr 7, 2011
    Oddometer:
    57
    Fine tuned the timing to simulate points at 014 and routed the new ignition wiring through the key switch (no kill switch). Tidied up the install and put it together for a test ride. It runs great! The lighting/ battery charging is going to have to wait for a while since I need the lift for a couple other projects before summer. At least the bike is usable for its intended purpose which is introducing big kids and young adults to the joys of the trail......when this virus stuff finally lets us
    #12
    greasyfatman likes this.