Redback Motorcycle Smash Repairs - 1/ 9 Collie St, Fyshwick. Ph: 6280 5433

Reg/rec ballsed

Discussion in 'Tech Help' started by Snab, Mar 24, 2016.

  1. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Hey champs,

    My reg/rec on my z650 is ballsed - multimeter readings at the battery when the battery is idling is all over the shop, jumping from anywhere between 1v and 14v with pretty much anything in between, and this is regardless of engine speed. Doesn't seem to be boiling the battery or flattening it, though.

    I've never seen a reg/rec/alternator failure like this before - I've seen them undercharge, or boil a battery, but in either case multimeter voltage readings have been consistent in being either under 13v or over 15v.

    Has anyone seen this happen?
     
    #1
  2. John.R
    Offline

    John.R Member Supporter

    Joined:
    Oct 8, 2011
    Messages:
    1,859
    Likes Received:
    585
    Location:
    Somewhere between pyschotic and ironic
    Real Name:
    JR
    Bikes:
    2012 R1 Raven
    CRF450X/Supermoto
    KZ750E Project.
    I would be running the whole series of tests if I was you.

    Testing voltage out of the stator, and testing the diodes in the reg/rec.

    Whats the highest voltages you were getting?
     
    #2
  3. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Cant remember specifically but definitely nothing higher than 14
     
    #3
  4. vinniebarbarino
    Offline

    vinniebarbarino Member

    Joined:
    Sep 10, 2007
    Messages:
    567
    Likes Received:
    11
    Worth checking; Earths, continuity/ resistances in the stator.
    There is an excellent fault finding chart on the GS Resources website.
     
    #4
  5. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    I disconnected the reg/rec and the bike certainly idles a lot smoother, but voltage readings from batteries are still fluctuating. The plot thickens.
     
    Last edited: Mar 25, 2016
    #5
  6. Jimmc
    Offline

    Jimmc Member

    Joined:
    Nov 3, 2010
    Messages:
    1,146
    Likes Received:
    185
    Location:
    Giralang
    Real Name:
    Jim
    Bikes:
    Honda VFR800Fi 2000(Rose), CBR600F2 93, CBR600RR 07 Tracky and 2002 CBR600F4i(Wattle).
    Sounds like you found it. Why wait for it to damage something else. A couple hundred dollars and then check the other elecs.
     
    #6
  7. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    yeah I measured alternating current at the battery while the bikes running and got 30vac, so definitely isnt being recitified. The weird thing is, though, is that I still get alternating current readings from the battery when the bike is shut down. Anyone know whats the deal with that?
     
    #7
  8. supamodel
    Offline

    supamodel Secret Aaaaaagent Man Staff Member Moderator Supporter

    Joined:
    Dec 19, 2007
    Messages:
    15,762
    Likes Received:
    2,190
    Location:
    Perth
    Bikes:
    Ducati MS2R1000; Yamaha RD250LC; Honda CT110, C90 Supercub; Suzuki GSXR750M, GT250L, TS250x, DRZ400E
    https://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

    Go through this methodically.

    It does sound like the rectifying part - I'm no Kawasaki expert, but in some old bikes this is separated from the voltage regulator - is not working. I need to think about the whole RMS thing but I am pretty sure seeing 14ish V DC on a multimeter probably implies 20ish V AC.

    The alternative is that the stator is unhappy and not providing enough current and there's something else going on.

    You can, with a bit of wiring magic, adapt a 3 phase modern reg/rect from a modern bike to many oldschool things with a bit of thinking. Beyond the level of thinking I'm prepared to do not for my own bike :D but it is possible. (Usually the 3 outputs on really old things are split differently, with one phase pretty much dedicated to lights, but that's where a bit of work is needed to be done to rejig stuff to a more modern way). Z650 might be new enough that it's practically done like a modern bike in which case there's less cocking-around needed.
     
    #8
  9. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Cheers dudes - yeah its definitely not rectifying - and its a five wire reg/rec with the three stator phases in, and two out - so its more or less the same as a modernish reg/rec. I found a youtube video that pretty much shows what my bike is doing -



    I'll source a new one and if that doesnt sort it I'll kill something/take it to a pro. Hope it aint the stator.
     
    #9
  10. G-relk
    Offline

    G-relk Moderator Staff Member Moderator

    Joined:
    Jan 14, 2014
    Messages:
    478
    Likes Received:
    170
    Location:
    Nicholls
    Real Name:
    Charles
    Bikes:
    2004 Triumph Daytona 600
    I've got a spare you're welcome to. It came off an R1.
     
    #10
  11. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Hey man, thanks but no thanks. Mines actually got a separate regulator and rectifier, so the wiring would be hell different. I believe the voltage regulator is working fine, and i hope the failed rectifier hasnt fried the regulator but I dont think it has. If so, it just means an extra week waiting for shipping
     
    #11
  12. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    So I ordered a brand new aftermarket regulator unit and rectifier unit from a dude who gives a lifetime warranty on the parts. Multimeter readings still the exact fucking same. I swear to god I'm going to kick this piece of shit out the window.
     
    #12
  13. G-relk
    Offline

    G-relk Moderator Staff Member Moderator

    Joined:
    Jan 14, 2014
    Messages:
    478
    Likes Received:
    170
    Location:
    Nicholls
    Real Name:
    Charles
    Bikes:
    2004 Triumph Daytona 600
    Try a different battery?

    Having been through charging system issues myself, I know your pain. Not fun at all. Good luck!
     
    #13
  14. John.R
    Offline

    John.R Member Supporter

    Joined:
    Oct 8, 2011
    Messages:
    1,859
    Likes Received:
    585
    Location:
    Somewhere between pyschotic and ironic
    Real Name:
    JR
    Bikes:
    2012 R1 Raven
    CRF450X/Supermoto
    KZ750E Project.
    I did something similar till I realised I wasn't doing the measurements correctly. Double check your multimeter settings.

    You need it on VAC to check voltage from the phases of the stator, and VDC for battery/regulator side.
     
    #14
  15. Yedi
    Offline

    Yedi Guest

    It's a floating neutral(ground). Best bet is a loose connection/broken wire somewhere on the ground side of the charging circuit (most likely in the stator itself, though for your sake I hope not)... I wish you the best of luck finding that though, it'll be a massive PITA
    Yup... Dividing RMS by 0.7 gets you near enough to peak measurements to not quibble over the difference :up
     
    Last edited by a moderator: Apr 13, 2016
    #15
    John.R likes this.
  16. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Yeah the thing is though, while AC readings are stable, DC readings are all over the shop from the battery terminals. Anything between 1 and 13 and jumping around every half second or so - I've never seen that happen.
     
    #16
  17. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Fuckit! Booked into Bruce's on Monday.
     
    #17
  18. Yedi
    Offline

    Yedi Guest

    Yeah, exactly. Each of the coils is ok, the issue is most likely where they all connect together (the 'common' or 'ground' point) which is causing massive fluctuations in voltage across the negative terminal of the battery...

    Voltage is a measurement of potential or, more accurately, a difference in potential between two points. As the voltage changes on the ground point it will show as a change in potential across the battery. For example, when your meter is showing 13V at the battery that is the difference in potential between only the positive and negative terminals. When it fluctuates and shows 1V, it's because the negative terminal now has 12V on it which it is picking up from a bad connection in the charging circuit...

    Knowing what the issue is doesn't however make it any easier to find the exact point and make a repair...

    This is why I'm an electrician and not an auto electrician (vehicle electrics run on black magic :p)
     
    #18
  19. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    It really is a dark art. Hopefully they have a magicians can find whatever the bad ground is, or bad stator, or bad juju, or whatever the fuck is going on
     
    #19
    Yedi likes this.
  20. Snab
    Offline

    Snab Member

    Joined:
    Jun 11, 2010
    Messages:
    638
    Likes Received:
    32
    Real Name:
    Aloysius T Dudefella
    Bikes:
    1976 Kawasaki Z650
    Bruce is 99.9% sure hes found the short, but the charging system is still ballsed despite the new reg/rec. I suppose the rotor/stator is next - maybe needs a re-wind, or maybe some bushes are dodge.
     
    #20