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VTR250 electrical problem

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by magin, Aug 14, 2012.

  1. Hey Netriders,

    The other day I went to start my vtr250... turned the key to on position, lights were working fine etc, and then pressed the starter button. I heard a "click" sound and all the bikes lights, starter, etc went off and stayed off.

    So I turned the key between the on and off position and then back to on, and noticed that there was no power to anything on the bike, lights included.

    I checked the voltage across the terminals of the battery with no load (i.e. key turned to off position) and it was 12.8 volts. I then turned the key to the 'on' position and the voltage dropped to practically zero (It was in the range of millivolts). Obviously lights etc were not lighting up and the bike seemed 'dead' during all this time.

    I (maybe foolishly) tried push starting the bike, followed by jump starting. When jump started, the bike would run, not well, with the headlights and neutral indicator flashing with the cars ignition. I didn't want to stuff anything up more, so I turned the bike off straight away.

    Prior to this, the bikes battery was sounding a bit "anemic" and I thought I was going to have to replace it soon anyway, although I do not want to go stuffing up a new battery and wasting money if I have other electrical problems.

    Any ideas what could be wrong?

    p.s. I had my chain and sprockets replaced the other day. I was planning to learn to fit them myself, but had the bike at the mechanic for major service including valve adjustments, steering bearing replacement etc. When I removed my rear wheel to fit a scottoiler dispenser mount to the rear wheel spindle, I noticed that a nut had come loose off my rear sprocket. Should I apply a particular kind of thread lock? I also noticed that the rear axle had not been greased, or at least became dry in the 200 kms since being at the mechanics. Should I take it out and apply (or reapply) grease to it?
  2. check fuses
  3. I had the regulator/rectifier go on my VTR. The mechanic said it was common on the VTR.

    As I understand it, it's responsible somewhat for charging the battery from the engine, so when it's busted, the battery gets no juice and slowly dies.
  4. Same thing.... Had it start smoking
  5. I checked the fuses and can't seem to see any that are open. The weird thing is though, I can't see how a fuse could do this. Why do I get voltage across the terminals with no load on the battery (key off position), but when I turn the key on, I get no voltage. I was thinking maybe the battery catastrophically failed somehow? So it makes voltage when no power is being used, but when the smallest amount is being used, ion diffusion within the battery does not occur fast enough.

    If I hook a car battery up to the bike, and the bike works fine, would it be safe to assume the battery had stuffed itself?
  6. i had the same problem, but only when i started the bike standing next to it. if i sat on it, it would fire first time.

    Then i sent it in for a standard service, and not a problem since.

    So really, cant give you any help. Sorry
  7. Are the regulators/rectifiers expensive? If they are cheap enough, I would probably just buy one and a new battery and replace both without actually working out what is wrong.
  8. newguy, maybe there was a connection that was loose, and sitting on the bike squished everything into a more reliable connection? Ha beats me though.
  9. 100ish...
  10. You have a short in the system. Starts with the starter relay, ignition barrel
  11. Yeah, I thought it could be a short... but, the battery wasn't feeling at all warm when I had the key on the "on" position, which led me to think that that wasn't the case. I'll give it a good look though. Maybe the click I heard was the relay stuffing?

    Thanks for all the advice people.
  12. A short would make a real lot of sense with the 12.8 volts across the battery with the key in the "off" position and millivolts across the battery terminals in the "on" position hey?

    I think this is going to be a tricky and time consuming problem. And maybe VTR250's poor regulator reputation is going to cloud my judgement (even if the poor reputation is completely deserved)
  13. It is more than likely regulator and the battery is stuffed, but there are some tests you can do. Take the battery to a Battery World or so and have it tested. If it fails buy a new one. Step 2 is to put your new battery or if the old one is OK charge it up and put it back in. See if you get the same collapsing voltage symptom when you switch the bike on. A short heavy enough to collapse the voltage of a healthy battery will be getting hot and making smoke.

    Disconnect the regulator and see if you can start the bike, measure the voltage between each of the three wires coming from the alternator (AC Volts) careful there will be 40 - 80 volts and should be roughly equal in voltage wire 1 - 2, 2 -3 and 3 - 1.

    If that's the result your alternator is intact, stop the bike, replug the regulator in, check the battery voltage doesn't collapse. Start the bike, measure the voltage across the battery when revving the engine, you should be getting about 13.8 - 14.4 volts. Higher than that or lower and the regulator is stuffed.

    Good Luck. :)
    • Like Like x 1
  14. thanks for all the help, especially cjvfr!

    Spelling out a process to solve my problem like that is incredibly helpful for those who do not know any auto-electrics!
  15. Hello netriders,

    Went to a battery store and had them test my battery. Sure enough, they get 12.8 volts across the terminals, but then they put a light globe across the terminals, it wont even light.

    So I put a new battery in the bike and it starts and runs fine. Checked the voltage across the terminals while running it to see if the regulator is working normally. Sure enough, independent of the engine speed, the voltage is about 13.8 volts. The weirdest thing though, is that when its idling, the voltage increase to about 14.4.

    I was expecting it to be like 13 volts idling, and then ramp up to about 14 when increasing revs, and then stay at that voltage, but who knows. All seems to be in order though.
  16. Good to hear you are back mobile again. The voltage thing may have just been the voltage recovering after the start, it will take a while to build back up to float charge level. 13.8 - 14.4 is good though you are in the charge region. Job Done :)