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What is it and why does it smoke?

Discussion in 'Technical and Troubleshooting Torque' started by davway, Nov 26, 2007.

  1. ok, if this was on an RC car, id know it is a heat sink, but its not so i dont have the faintest idea what it is or what its for.
    i dont even know what its called so i cant even help myself on this one.
    anyway, a little back ground:
    a few weeks ago, i went to start the bike and the battery was flat. unusal, even for 2 weeks but didnt think much of it.
    jump started the bike off the Fairlane (which also had a flat battery) and as soon as i took the jumper leads off, the bike would stall. definately time to put the battery on the charger - very unusal.
    so, after a couple of minutes with the bike running, getting its power from the fairlane, i can smell the dreaded burning electronics smell. pop the side cover, restart the bike and its smoke season. smoke pouring out of this thing. stop the bike and the smoke stops.
    the fuse isnt blown either.
    now, youll notice in one of the pics that im pointing at a plug on the bottom of it. if i unplug this, it doesnt smoke. everything still works (lights, blinkers - everything).
    so, what the hell have i done?
    why did it do it in the first place?
    what is 'it'/purpose of 'it'
    and what do i need to do to fix it?

  2. Looks like a rectifier to me (without knowing the bike in question).

    If that's failed then your battery won't charge (or at least won't charge properly).

    Honda VTR1000's are notorious for that particular fault but it is fairly common on lots of bikes.

    *edit* The backside of many rectifiers have heat sinks attached because they can get quite hot due to the high current flow, so you're partially correct... the bit we can see in the picture is a heat sink.

    *edit 2* If you unplug it then you'll get zero charge... your bike will only run until your battery goes flat. You need to replace the unit (assuming it's faulty) with either a good 2nd hand one or an exchange one or a new one. Rectifiers don't tend to be cheap I might add :(
  3. It's a regulator aka rectifier. It smokes because it is phucked.

    Your battery won't charge without it or it it's not plugged in.
  4. This is a common Honda fault. They make their regulator/rectifiers out of jelly. You'll need a new one, or a secondhand one from the wreckers.

    Do some research, you might find out that Firestorms will accept a unit from another type of bike - in which case it should be loads better than a Honda one. From memory Vic's running one from an R1 or something in his, why not drop him a PM.
  5. Isn't this a Suzuki GF250?

    If it is, at a bet I'd say many Suzuki items will fit
  6. it is a 84 Suzuki GS250FWS.
    it must have been replaced at some stage before as it has 84 TSX 250 written on it.
    anyone know where i can find out what will fit from other more popular bikes?
    im gonna call it phucked anyway, when it smokes there a nice runny stream of black melted electronic circuit board dripping from the back of it.
    at least i know why the battery wont hold a charge any more.
  7. Electronic devises rely on keeping the smoke in to make them work. If you let the smoke out, they don't work.
  8. lol, yeah i know that.
    its gotta have factory smoke for it to work :LOL:
  9. While most folk use the terms interchangeably they are two separate items, although they might be incorporated in the one housing.

    The rectifier (the big bit with at least 3 wires going to it from the alternator) changes the AC to DC to charge the battery. The regulator (with the biggish wire ultimately going to the battery + terminal) keeps the voltage output below 14.8 volts or thereabouts, to avoid overcharging.

    But you are right that most people don't care less until the thing stops working... ;-)

    There are cheap(er) aftermarket alternatives advertised in AMCN, I think. Or Cycletorque (the freebie found in better bike shops everywhere).


    Trevor G
  10. I was quoted $120 for a second hand R1 one from a wreckers.
    I ended up buying an aftermarket one, new, for $160
  11. [​IMG]

    :LOL: :cool:
  12. Hey don't buy that Lucas smoke!

    Bloody Prince of Darkness stuff that is :LOL:
  13. Lucas isn't that bad.. :evil:

    Their light switches have THREE positions! :cool:

    Dim, flicker & off.. :LOL:
  14. well ive just been in contact with my parts supplier who has offered a Honda rectifier/regulator to replace the one on my bike.
    he also asked if the alternator had been checked.
    should it need checking and how do i check it?
  15. So in a way they invented fuzzy logic.

    Macca, great picture.

    Trevor, you are of course right. The Suzuki rectifier may even be in the alternator like a car (I believe mine is).
  16. Maybe, but I doubt it. There is more cooling area when it is mounted on the frame somewhere, rather than stuck inside the heat of the engine.

    Car alternators are usually exposed to a good stream of moving air - bikes' are usually trapped inside the engine cases.


    Trevor G

    PS Apostrophe use is correct, replacing or substituting the word alternator used earlier in the same sentence.

    Yamaha do a few external alternators...
  17. Interesting I just checked my workshop manual.

    They refer to it as a regulator only and it is contained within the alternator. No mention of a rectifier but if you look at the electrical schematic it is drawn as a rectifier (6 diodes).

    though there is a small unnamed box near an earth local to the alternator.