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Motorcycle Won't start! Please watch Video!


Approximate state-of-charge

Open circuit voltage



100%
75%
50%
25%
0%


12.65
12.45
12.24
12.06
11.89​
Table 1: BCI standard for SoC estimation of a maintenance-free starter battery with antimony. The readings are taken atroom temperature of 26°C (78°F); the battery had rested for 24 hours after charge or discharge.
 
12.8 is indicative of a fully charged lead-acid battery. But ... It is one thing for the battery to have "volts", it also needs to deliver "amps". And your charging system still needs to be checked.

Put the battery back in the bike now. Try to start the engine. It should crank vigorously and start right up. If it cranks slowly even though it has "volts", it means the battery is not delivering "amps" (current) - it can't provide enough load. That means the battery is toast. Replace it.

If the engine starts, now check the voltage across the battery terminals (A) at idle, and (B) at 5000-ish RPM. Proper charging voltage should be 13.5 to 15.3 volts, ideally 14-something. It is possible that the charging system doesn't deliver full voltage at idle depending on how much load your bike has (lighting, ignition, accessories), but it should certainly deliver proper charging voltage at higher engine speed.
 
12.8 is indicative of a fully charged lead-acid battery. But ... It is one thing for the battery to have "volts", it also needs to deliver "amps". And your charging system still needs to be checked.

Put the battery back in the bike now. Try to start the engine. It should crank vigorously and start right up. If it cranks slowly even though it has "volts", it means the battery is not delivering "amps" (current) - it can't provide enough load. That means the battery is toast. Replace it.

If the engine starts, now check the voltage across the battery terminals (A) at idle, and (B) at 5000-ish RPM. Proper charging voltage should be 13.5 to 15.3 volts, ideally 14-something. It is possible that the charging system doesn't deliver full voltage at idle depending on how much load your bike has (lighting, ignition, accessories), but it should certainly deliver proper charging voltage at higher engine speed.
Alright thanks will check and do this all tomorrow
 
Any new updates on this?
Well after starting it and running it. The voltage dropped to 12.74 (also after sitting for 1 day) so I'm assuming either he battery has dissipated yo the proper voltage or its a bad battery. I'll have to check the voltage again since it sat for the weekend
 
usually batteries do not lose charge "over the weekend"...Mine sits on the bike for 2 weeks before I take her out for a long spin and bring her back....

May be you should look at the charging system( rectifier/regulator/alternator)..

BTW, how old is your battery?
 
usually batteries do not lose charge "over the weekend"...Mine sits on the bike for 2 weeks before I take her out for a long spin and bring her back....

May be you should look at the charging system( rectifier/regulator/alternator)..

BTW, how old is your battery?
Well I honestly have no idea how old the battery is because I bought the bike 3 weeks ago... it's a 1988.
And we'll I charged it and an hour later it read 12.81 then the next day 12.74 and that's was a week ago. I'm hoping I can check it again some time soon
 
I think you can take it to crappy tire where they can put the battery on a tester and give it load and see if it holds charge...for a small fee...

you can then decide if you need a new battery or not....if they check and see it is ok, then you need to look at charging system...

I am assuming you do not have alarm or fancy led lights or speakers and other electronic aftermarket stuff on the bike ( the speedo of tht cbr looks newer than '88 )
 
I think you can take it to crappy tire where they can put the battery on a tester and give it load and see if it holds charge...for a small fee...

you can then decide if you need a new battery or not....if they check and see it is ok, then you need to look at charging system...

I am assuming you do not have alarm or fancy led lights or speakers and other electronic aftermarket stuff on the bike ( the speedo of tht cbr looks newer than '88)
It's got a custom cluster with a little digital clock....
And if something is wrong with the charging system how much would that cost to fix "roughly"
 
TBH, I dunno how your charging system works...mine has the regulator/rectifier unit combined into one housing and my owner's manual shows a simple method to test it using the multimeter... its a $30 part for my ninja, I suspect it'll be cheaper in your case, but you must know the location of these units on your bike. If they are ok, then the alternator is the next suspect, but I wouldn't tackle that job unless I'm absolutely broke!

EDIT: if you really do not know how old your battery is then may be you should get it checked....does it need water? or is it maintenance free....either way, getting it checked may be the cheapest way. Jap bikes are bullet proof man..charging sys may be ok but the battery may be on its way out. Some one correct me if I'm wrong please!
 
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Well after starting it and running it. The voltage dropped to 12.74 (also after sitting for 1 day) so I'm assuming either he battery has dissipated yo the proper voltage or its a bad battery. I'll have to check the voltage again since it sat for the weekend

You have not done the test described in post #23.

Troubleshooting MUST be done diligently and systematically to properly identify which parts of your bike are working properly and which parts are not.

The other thing that you have not told us is make, model, year. There are a few different variations of charging system circuits and layouts.

Now ... Follow these steps systematically, don't skip steps, and don't wait for weeks between steps.

With the key off, measure the voltage across the battery terminals. If it is more than 12.45 volts (more than 75% charged), carry on with this procedure, otherwise put the battery on a charger for a couple hours then wait and hour and re-check. Again, if it is more than 12.45 volts, carry on. Tell us what this voltage is.

Report whether the engine cranks vigorously and starts the engine, or cranks weakly and barely manages to start, or cranks weakly and doesn't start, or just goes "click" when you press the starter button accompanied by all the lights going out, or if nothing happens whatsoever. Select one of these descriptions. Report to us which one best applies. If there are other symptoms of note (lights on, lights off, etc) also describe.

IF the above step resulted in a successful starting of the engine, then with the engine idling, report the voltage across the battery terminals.

Then raise engine RPM to around 5000, and with the engine running near that speed, report the voltage across the battery terminals.

Be systematic and thorough, don't skip steps and don't leave out information.
 

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