2007 cbr 125 won't start unless jumped and only runs for a few seconds | Page 4 | GTAMotorcycle.com

2007 cbr 125 won't start unless jumped and only runs for a few seconds

These little bikes don't have much of a charging system. If the battery is cooked and dead as a doornail (which is highly likely, in view of what was just posted!) it's not guaranteed that the alternator will produce a sufficiently stable voltage with the engine at idle speed.

Ah, OK. I was thinking about my little Honda 90 with the Lifan in it. I ran it for a while just on the race wiring, it worked fine. And I have bump started when the battery is low, just fine. But I suppose I have never tried with a totally dead battery.

Edit: I forgot the Lifan was designed to run on race wiring
 
FFS - remove the battery and take it to a local shop. They should have a Yuasa master catalogue with dimensions and terminal locations even if the don't have one on the shelf. How long have you been dicking around with this ? You could be riding right now...
 
I don't have FI on any of my bikes - so I don't know what I'm talking about - but if you jump one with a dead battery, shouldn't the alternator be outputting enough at idle to keep it going?
On many bikes, you need to be up to 3000+ rpm before the alternator starts to make decent power. As Brian said, trying to charge a dead battery could easily exceed the output at idle.
 
These little bikes don't have much of a charging system. If the battery is cooked and dead as a doornail (which is highly likely, in view of what was just posted!) it's not guaranteed that the alternator will produce a sufficiently stable voltage with the engine at idle speed.
But it should have idled at least until the jumper battery was disconnected. So many details are unclear, and I restate that a video of the starting procedure would really help.
 
cnd tire should have the battery you require. Call the parts department and ask them to check for your year and model of bike. If they don't have it in stock they can check other cdn tires stores nearby too, or get it within days. The last time I went to cdn tire they had mine in stock. Try the phone. Make certain the battery is a sealed maintenance free battery.

make sure its installed properly!
black = negative -
red = positive +
 
I'm assuming you are new... so I held back.

Get the right battery for your bike, any bike shop or bike dealer should either have it in stock or be able to get it for you within a couple of days.

As Boyo says above, "pick up the phone"
 
I'm assuming you are new... so I held back.

Get the right battery for your bike, any bike shop or bike dealer should either have it in stock or be able to get it for you within a couple of days.

As Boyo says above, "pick up the phone"
held back what being dick? Why is it that some of you in here don't understand that some people are here for help and not just to put others down and let them know your a manly man. Grow up, some people don't know everything but would like to learn. If you have so much disgust toward a tread don't reply to it. Easy as that. Thank you everybody who is helping and being respectful.
 
Not disgusted, amazed that it takes so long for some people to understand simple concepts.

and yes...I'm a dick sometimes
 
I have Fi bikes with no battery. All it takes is a quality 3 phase alternator, a healthy capacitor and a higher then normal engine idle.

The problem with a 'dead' battery in the bike is that if the cells in that battery are shorting out, that will kill the voltage the fuel pump needs.
Better to have no battery on the circuit at that point then a bad one if you hope to run it totally off the alternator, such a bike would still need a capacitor if there is no battery to assist, or your voltage would be spiking all over the place.

lol I've always had patience, I trained a monkey to ride my tricycle when I was 6.

... This place is really good batteryoutlet.ca but they are only in eastern ontario.
 
Last edited:

Cbr125guy

Active member

Sep 12, 2019
"How just so I can find one soon if I need, what battery does it take and where would be my best to find it?"


You posted that on Sept.12....there have been many helpful replies since then....yet you are still posting today....12 days later
 
OP, where are you located? Maybe someone is willing to drop by and take a look. Should take 5 minutes for someone with experience to diagnose it. Or at least point you in the right direction.
 
Shipping on the cheap one is weeks. Batteries are something where online is a dumb idea. Shipping drives the price up and if you have any problems now you have to deal with return shipping. Why do you continue to completely ignore every suggestion to go to a real brick and mortar store? It's not based on patriotism, it's based on years of experience solving the problem you have.
 
Yep, is the international shipment of battery acid that is causing you grief.
Buy from a battery specialist like the one I linked, they will take good care of you because you are young and will be buying tons of batteries in the future.

Oh, and they want your old battery in exchange to get the good price btw.
 

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