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Aprilia RS125 '09 battery problems

Discussion in 'Technical and Troubleshooting Torque' started by AshRS125, Feb 8, 2010.

  1. Hi,

    My fairly new rs125 (600kms) reguarly doesn't start. Here is what I know

    It will start with a push start
    The charge LED says around 12v most of the time when trying to start
    Charge LED says around 14-14.8 when riding
    I have had the battery tested, okay
    It will start if I have ridden it for a while but if i leave it 1-2 days without riding it won't start.
    It is summer here, 35C most days
    Have tried choke

    It seems as though the battery is losing its charge very quickly, is there a way to reduce this? Should I need to? I have read about removing the 20A fuse while not riding the bike for awhile but dont know which 20 fuse that is.

    Can someone tell what their rs battery charge is before starting?

    This problem is very frustrating for having a new bike.

    Thanks for your help,
  2. Normal battery voltage before starting is around 12.3 volts. Your voltages seem fine, and the charging (riding) voltage is no worries at all.

    It may be just that you haven't gotten used to the bike yet. Running 98 will help starting over running 95, and also make sure the fuel tap is in the 'on' position. Ensure the kill-switch is in the run position. Choke on, few throttle turns before hitting the starter and then hit the starter with no throttle. Turn off choke as soon as possible (definitely by the time coolant hits 40'C).

    Still worried? Check the battery fluid level. It should be on a level surface while you do so. The fluid should be between the two lines on the case. If not, buy some distilled water and top it up with a syringe via the small caps on the top of the battery. Afterwards, put the battery on a charge overnight. Ensure no naked flames around when charging as charging creates flammable gas.

    You may also want to treat the battery with 'battery reviver' or similar, I get mine from SuperCheap in the battery section and swear by it. Around $10 for a bottle that will treat several batteries and prolong their life.

    If none of the above helps you may just need a new battery. Try a sealed unit, they're better than the standard lead-acid type. You need a 9 amp-hour 12v battery, but I ran my '01 RS125 with a 3 amp-hour battery for almost a year with no problems.

    Cheers - boingk
  3. Following from your advice there Boing, the OP has the exact same bike model as mine.

    I use 95 BP premium, so not too sure if that's the issue but perhaps something to dissect. It seems as if the battery is just not performing correctly, because I dont see why there would be other components in the engine doing this. Did you play around with the idle nut under the seat? What's the needle sitting at on idle?

    I'd advise not to tinker around too much and just take it straight to the dealer, which I am assuming you bought since it's brand new. You have the warranty so definitely take it up with them.

    I feel for you mate. It's tough considering its a new bike thats already causing issues. Mind you, I wouldnt ride for a week, rain hail and shine, and my bike will start after 2-3 turns with choke for 5 seconds. I'm sure other RS owners can chime in here.
  4. Thanks guys,

    I have only ever used 98 petrol, no problems there. One thing I forgot to mention was that I have terminated some electric wire from the batter to the outside of my bike for charging. Should I remove these? Would they be draining charge?

    It is quite possibly just my inexperience with bikes and starting. I did not know of the technique to throttle on before starting. I will try this. I had been giving a bit of throttle as hitting the starter.

    So just to be sure, best process for starting

    Ignition On
    Killswitch set run
    Bike in Neutral
    Choke on (all the way? half? In summer is it necessary?)
    twist throttle twice
    hit starter

    I will look into a trickle charger and the battery reviver.
  5. Sounds like u answered your own question.. Be very cautious with electricals next time.

    If in doubt talk to your dealer anyway.

    The way I do it is all the steps you mentioned, but put the choke on full. I'd suggest 5-10 seconds max and just turn it off. Works like a charm for me. The needle should sit at 1500rpm.

    Have u had your first service yet?
  6. so i got a mate round that knows a bit about bikes and it was actually a fouled spark plug. Will at least I hope so, getting a new one tomorrow
  7. Was going to suggest a new plug. Service intervals for these are around 4,000km and you should be using NGK BR10ES, not the BR9ES as stated by some. The 10 is the standard plug for the 'full power' bikes we get delivered here and says so in the user manual. Using a 9 could cause damage such as pre-combustion (which in time may hole the piston).

    You could also try just cleaning the old one up an trying again once the battery is charged, usually works for me. BTW, I got almost 8,000km out of my last NGK BR10ES plug before it needed replacing. Even then it could still have probably been saved by cleaning and regapping to spec.

    Cheers - boingk