First time poster here.

I have a 2010 Kawasaki Ninja 250 - this is a bit of a story and I try and keep it short.

A couple weeks ago my bike was having trouble - when I would rev the engine in low speed the engine would start to cut off. I thought this had something to do with my carb since something similar caused issues a few years back. I kept on reving the engine and eventually I was able to get up to higher speeds without the engine cutting off.

During my next ride to work it was running fine. Then when leaving work it would not start, I would turn the key and nothing was to happen (just a single tiny click of everything turning off). First I thought it was the battery (I checked that by beeping the horn - which sounded great). My friend help me push start the bike and we got it on and going about 3 mile/hr at about 1 RPM (I think) anything above that there would be a really loud bang noise. Also the RPM pin was upside down and below the 15 RPM (it was just jumping around in full circles).

I heard it might be the battery causing the issues so I took the battery out to charge it over night before trying the bike again. I set the battery back in the bike and tried it again - nothing. But I also noticed the battery boiling/bubbling a little. I looked it up and I might have destroyed it but also might not have (I have yet to test it and see if I need a new one).

There aren't really any motorcycle sport bike repair shops near me. I need some guidance and help on diagnosing and fixing my bike. I have the Owners Manual, and Haynes Motorcycle Service Manual. I'm honestly not sure how to even figure out what is wrong with my bike.

Any help would be really appreciated.

  • Welcome to Motor Vehicle Maintenance & Repair! Commented Sep 1, 2018 at 13:15

2 Answers 2


It sounds as though the battery is at fault to me. The fact you charged it and boiled it means it will most likely need to be replaced anyway. This is electrolyte and water which you've boiled out of the battery. You could have left the plates dry, which would make it so there's no electron path and and therefore the battery is dead. You can try putting distilled water into the cells and see if this helps. It's been my experience, when you boil a battery for whatever reason, you've usually done irreparable damage to the battery. The other symptoms you've given are typical of a bad battery. A horn doesn't require as much voltage to sound, while electronics are not as fault tolerant (thus the crazy things you saw on your gauges).

You can also check your battery by putting a digital multimeter on it, which would give you the voltage. It should be in the 12.5-13.2VDC range. If you're getting nothing, or very low voltage, this would be another indicator the battery has gone bad, especially after charging it.

  • "You could have left the plates dry" - do you mean that this happened while I was charging my battery overnight? I read online that if the horn works well then its probably not the battery that is why I suspected it was something else, although it makes complete sense that it uses less power than some of the other electronic parts and works fine even on a low battery. I do not have a multi-meter, but I guess I should just go out and pick one up.
    – Ely
    Commented Sep 1, 2018 at 14:10
  • @Ely - Yes, when you charged the battery. You stated you checked the horn before you charged it. As I stated, you can try to refill the cells with distilled water to get them to work again, but if you've boiled the battery, you've more than likely done irreparable damage to the battery. Commented Sep 1, 2018 at 14:26
  • Is there something I can do to check if it irreparable? I'm not clear on how to refill the cells? Can you provide a link or something.
    – Ely
    Commented Sep 1, 2018 at 14:30
  • @Ely - There are either going to be vented caps you can take off of the battery or not. if you can take them off, you can add water. if not, it's a done deal. Commented Sep 1, 2018 at 15:11
  • There are no vented caps. So I guess its busted.
    – Ely
    Commented Sep 1, 2018 at 15:25

Did the battery “boil” or “gently bubble” while charging? Gentle bubbling is usually fine, but boiling - like a kettle is not.

Did the battery or any single cell “boil” under load, such as when operating the starter? If it did, then the battery needs replacing.

Make sure the new battery is fully charged overnight - some batteries are sold as “fully charged, ready to go” but some car electrics and bikes prefer a properly charged battery.

  • I think it was more of a gentle boil when I tried starting the bike. Does this explain the problems I was having before the battery stopped working? Also I have read things online about overcharging - What is the preferred method to charging but not over charging?
    – Ely
    Commented Sep 1, 2018 at 14:06
  • If it boiled when you tried to start it, then it needs replacing. As for charging, MOST chargers sold now are "smart" and decrease the charge output as the battery increase its level of charge. Only old, basic chargers don't have much control.
    – Solar Mike
    Commented Sep 1, 2018 at 14:17
  • I'm pretty sure I have an old one that has no control it claims to have 13.6 - 14.8V and 1000mA. Any idea how I can use this charger to charge up a new battery that I purchase?
    – Ely
    Commented Sep 1, 2018 at 14:28
  • The one you link to does say on the first point that "it will NOT charge when the battery is full"... It also has the word "SMART" in its title... By "old" chargers I mean just ones that were a transformer, rectifier and two leads...
    – Solar Mike
    Commented Sep 1, 2018 at 14:34
  • I feel that even though it says "Smart" it probably isn't. But that's good news.
    – Ely
    Commented Sep 1, 2018 at 14:35

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