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motorcycle wiring

Discussion in 'Modifications and Projects' started by ben1100, Aug 1, 2012.

  1. I've got a 1983 yamaha xj900 that i've stripped into parts.

    In a few months [when i finish uni] I'm going to replace all the engine gaskets, clean everything and put it back together, doing pretty much everything by myself. only problem i have is that i know absolutely zero about motorcycle wiring.

    Does anyone know how to rewire from scratch a motorcycle? or know someone who does?
    I want to learn how to rewire a bike and restore the most important functions such as basic running lights and getting the engine to run :)
    basically do wiring that will be sufficient to pass roadworthiness.

    any answers appreciated :D

  2. If you have the original looms, just duplicate them!
    All different coloured wire can be bought (see Hella catalogue), even traced wire.
  3. I've done it a couple of times. It's a required skill for owners of old Suzukis :D.

    But I'm too far away to offer much practical, hands-on help. The best I can do is suggest you get hold of a manual with a good, clear wiring diagram. It doesn't matter if it's for an overseas model. There may be minor peripheral detail differences but the important bits are the charging system and the ignition system, neither of which would change between markets.

    Treat the wiring on a system by system basis. See what connects to what in the ignition system so the bike will, at least, run. Then trace the charging system and wire it up. Then the lights, then the horn, then any trivial shit that Yamaha chose to fit.

    I don't know if you're going factory original or thinking of upgrading. I'd recommend going up a wire size for everything, wiring big loads like the headlamp and horn through good quality relays, fusing everything and ditching as many of the idiot systems as you possibly can.

    And, FFS, use something better than those disgusting Durite crimp on connectors that I see everywhere.
    • Like Like x 1
  4. i chucked it all out!! :eek:
    it was all in such crappy condition i just didn't think to keep it! damn, should've.
  5. thanks for the informative post patb.
    I should have a manual in the post in the coming week or so, that should help me at least get a better idea of what i need.
    I'm definitely looking to upgrade rather than copy the system, so thanks for the tip, i'll be sure to get better wires.
    what would you recommend as the best way to connect all the wiring? solder and heat shrink everything?

  6. funny you say that, a friend of mine who i convinced a few months ago to get his licence [and helped choose his bike] has some electric issues with his 1981 gsx400 [the awesome 4cyl 400cc one].

    we think theres a problem with the charging circuit.

    any tips? haha
  7. Buy a second hand one to give you a guide.
  8. might give that idea a go if im still lost when I have the service manual. cheers
  9. YOU IDIOT!!!! :rofl:
    I can sympathize with you!
    Same as mechanicals,,,never throw anything out until the job is done.
    Even the stuff you're replacing. :)

    Probably would work fine as a plug & play!!
  10. Almost certainly a dead rec/reg. Change it out before it takes the alternator with it. Back in the day, the cheap fix was to bung in a Honda CB250/400N unit. There was also a known fix using car parts but I can't remember what from now. These days, I'd be surprised if one of the classic Suzuki specialists didn't do an upgraded unit that will fit straight on. Make sure it's bolted down firmly to clean metal with a slather of heat-sink paste (get it from Jaycar or DSE) under it.

    Solder and heat shrink certainly have their place, but you'll want some detachable connectors to allow troubleshooting, component removal, etc. Have a hunt around on the net for electrical suppliers to the classic car restoration boys and stuff like that. I got a starter set of good brass crimp on spade and bullet connectors, complete with a selection of connector block bodies and a reasonable quality crimper from one of them, although it's so long ago now I forget who. They're not completely ideal for bikes as they're not terribly weatherproof but it's nothing that silicone sealant and electrical grease can't sort.

    There's nothing wrong with crimp-on, done properly, but the Durite shit is bulky, ugly, prone to corrosion, screams "cheap bodge" to the world and the crimping system doesn't work very well.
  11. lesson learnt haha
  12. thanks heaps for all the info patb, i'll tell my mate what you said about the rec/reg and get him to suss out a replacement.

    i'll go check out jaycar for the electrical stuff, pretty sure they'll have what your recommending.

    thanks again!