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79 motor, 81 wiring

Discussion in 'The Garage' started by Erspamer, Nov 20, 2013.

  1. Hello, I am new to this forum and new to xs650's so I apologize if this has been covered in the past. I have a 79 motor and a full 81 frame and wiring harness, I am looking for the easiest ( and least expensive) way to convert the older motors breaker system to work with the stock 81 electronic system. My concern is that I understand the 81 ignition box advances spark on its own and the 79 motor has the mechanical advance weights. Not sure of the best way to make this frankenbike to work properly without a lot of trial and error. I guess thisnisnyou guys come into play. Thanks in advance for all the help and sorry again if I'm asking something that's been covered extensively in the past.

  2. XSLeo

    XSLeo XS650 Guru Top Contributor

    Yes, it has been covered several times.
    The 70 to 79 use points. The 80 up use the TCI.
    To swap a points engine to a TCI bike just remove the points and associated parts, install the 80 up rotor and stator to the points engine.
    To install the 80 up engine to an earlier bike you need to install the bushings and seals in the cam then install the points parts.
    Do you have the 81 stator and rotor? If so just install them on the 79 engine. The 80 up TCI ignition works off these parts.
    Remove the points, advancer and advancer rod. Save them for when the TCI quits working. You will need some of those parts for the Pamco.
  3. Could I just leave the older style rotor ans stator if they are in good working order, replace the points with a pamco trigger system and wire the bike with an older style wiring harness? Are there any issues with doing it this way?
    Would I be creating even more problems? Since I do not have the 81 stator and rotor it sounds like the next step may be to go with the full pamco system for around $500, not my favorite option and I have heard those are a real bitch to get set up properly.
    Any thoughts?
  4. XSLeo

    XSLeo XS650 Guru Top Contributor

    Yes, you can use the 79 stator and rotor.
    The Pamco is an easy install. Just follow the instructions on Pete's Ignition website.
  5. Thanks Leo, you've been a lot of help. Starting with just a 79 motor and an 81 bare frame/harness leaves some challenges but it also gives many options!
  6. XSLeo

    XSLeo XS650 Guru Top Contributor

    If you look on Mike's kits with the ignition, coils and caps start at $142. This is the original basic unit that uses the advancer and rod from the 79 engine.
    This uses a cheap coil. Item # 14-0901.
    The same kit but with the better coil with replaceable wires, #14-0911 $170.
    The E-adavancer kit #14-0905 uses the cheap coil, $235 #14-0910 uses the better coil. $274.
    The first two use the advancer and rod from the 79 engine. The last two use just the rod.
    Any of these are easy to install and set up.
  7. Any advantage to the e advancer over the mechanical? Are there any reliability issues with the 79 style rotor and stator that I should be aware of? Yea the junk coil is not my preference so the better one will be the one chosen.
  8. XSLeo

    XSLeo XS650 Guru Top Contributor

    The stock advancer works fine. It needs regular maintenance to keep working fine. The E-advancer needs no maintenance. It also has features the stock advance doesn't. When the engine is turning less than 100 rpms the ignition gets extra retard to help prevent kick back when kick starting.
    The cheaper coil isn't junk but it has the plug wires molded in and makes changing them much harder.
    It works fine.
    On the 79 style rotor and stator, the reliability is the same as later units. The way the brushes are wired is different than the later units. So if you want to use the later combo reg/rec you need to do some wiring changes as well as the three nylon screws.

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