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Vtr250 battery issues

Discussion in 'Technical and Troubleshooting Torque' started by Leighbus, May 24, 2014.

  1. Bike sat for 3 weeks, went to start it this morning and it was completely flat. Tried roll starting it and couldn't get anything, then I jump started it off my car battery and it fired right up. I took the jumper leads off and it kept running, but when ever I rev it it starts missing and spluttering and the lights dim, connected the jumper leads up again and gave it a rev and it worked fine so it's definitely electrical issue.

    Put a multimeter on it while it was idling and was reading about 9 volts. I'm going to give the battery a charge overnight and try again tomorrow but can anyone tell me if its just a case of battery being too flat or maybe battery stuffed or something more like alternator not charging properly?

    I thought that if you got it started it should just run normally off the alternator otherwise you would never be able to roll start it if the battery is flat.

  2. To early to say, you will need to do some more diagnosis. If the battery has cells that have collapsed it may be pulling the voltage low even with the alternator charging. A jumper battery connected maybe able to hold the voltage up when the alternator can't.

    Charge the battery and measure its voltage before you put it back in the bike. If the voltage is lower than 12v then its probably a stuffed battery.
  3. I see your alternator is not working properly
  4. Put battery on charge yesterday arvo, took off charge last night before bed. Woke up this morning checked voltage still around 13v. Put it in bike started it up multimeter shows about 13.9 - 14v. Went for a 15 minute ride to my parents place checked it again and still the same, went for a further 40 minute ride no problems, won't be able to ride it till next weekend will have to check it again then.
  5. Everything so far sounds normal, except the battery going completely flat in three weeks. Either the battery is self discharging, which means it is near the end of its life, or there is something on the bike draining its power. Try disconnecting the earth lead, then attach multimeter, then touch earth lead to terminal on & off, and see if multimeter registers any voltage drop when lead is connected.
    • Agree Agree x 1
  6. I still don't understand why after jump starting the bike it wouldn't rev above idle.
  7. let me guess, lets say your alternator is not generating appropriate voltage what system needs, thn idle is ok

    but as you revving up, means that voltage between spark plug should be higher than idle.

    and your ignition coil does not retrieve healthy voltage from alternator, so it can not boost higher ignition spark voltage.

    im saying just one of possibilities.
  8. The battery being completely flat, would have been absorbing everything that the charging system could provide, with little left over for the ignition system. This is normal. Most motorcycle charging systems are not designed to charge a completely dead battery as well as provide power for everything else. Some might, but most will not. This shows you the importance of a good battery & good terminal connections, for proper running.