TOPIC:

Hi brand new owner of a 440, i am hoping to get it running and teach kids and short people on this little bike. She is all there and in good shape so really a diamond in the rough. the pressing problem is electrical.with the battery charger connected to the battery all the lights come on and the bike starts right up and runs great. As soon as i disconnect the battery ch.arger the engine quits and all the lights etc are gone.
The battery shows 12 volts and I think once the engine is running the bike should run even with out the extra from the charger.
Can anyone offer advice to where I should start looking?
Thanks everyoneteven
S

Starting and/or running a KZ engine while it is hooked to a charger or a running vehicle is a great way to kill the bike's electrical system. Ed

Bad battery

650ed wrote: Starting and/or running a KZ engine while it is hooked to a charger or a running vehicle is a great way to kill the bike's electrical system. Ed

Can someone smarter then me explain this?
I've read it here way too many times to not have some merit.
I understand the issue if running engine with no battery or no ground... possibly causing regulator/alternator problems.

TexasKZ wrote: Bad battery

Bingo


i feel stupid having introduced myself to this forum and it was so simple to fix. i dont know why the charger said charged but the battery was bad.

any sujestions on a new rear tire

missionkz wrote:

650ed wrote: Starting and/or running a KZ engine while it is hooked to a charger or a running vehicle is a great way to kill the bike's electrical system. Ed

Can someone smarter then me explain this?
I've read it here way too many times to not have some merit.
I understand the issue if running engine with no battery or no ground... possibly causing regulator/alternator problems.

Below is one reason. It mentions a running car, but a battery charger will also deliver very high amperage. The quote is from www.reynoldsmotorsports.com/get-charge-o...more--battery_basics I've also read other articles that state that the high amperage (up to and sometimes over 200 amps) of a charger can damage a bike's electrical and/or charging system.

Here are just a couple sites warning not to jump a bike from a running vehicle. The same advice would apply to a battery charger.
www.burlingtonharleyriders.org/safety/pd...20a%20motorcycle.pdf
www.motorbikelicense.com/can-you-jump-st...torcycle-with-a-car/
motorcycleviews.com/howtos/howtojumpstart.htm

"Can I jumpstart my bike with a car?

Yes, but only with the car turned off, i.e. not running. Motorcycle electrical systems work with a lower amperage then cars. Cars put out approximately 200 amps when running and motorcycles only put 32 to 40 amps when running. If you attempt to jump start your bike with a car that is running you could cause the battery to blow up, which can result in damage to your motorcycle and/or physical injury. I carry motorcycle jumper cables for when my friends' bikes have battery issues. You can jumpstart one motorcycle from another and the motorcycle can be running."

Interesting read.
The only parts that makes good sense to me is, if you have completely dead or defective battery.
Then the car's alternator and battery will see the dead/shorted battery as nearly a dead short across the battery plates to chassis ground and the car's Alt/Reg and car battery will try to dump extremely high current at around 15vdc-16vdc, into a very low resistance.
Then it is simple Ohm's law for power, showing you about anywhere from stone dead cranking power 500a-750 amps x 15v!
Even 15vdc at 200a (stated in the article) = 1000 watts of energy.... trying to be dissipated by a little motorcycle battery, who is built to handle maybe 200 watts max. I could see that battery spewing boiling acid after it splits a seam from overheating.
Same thing with any little wires that are built to handle under 20-40 amps or possibly zener diodes, or forward biased diodes in the regulator rectifier...??
Anyone else?

Is it possible that the high amperage might damage a field coil charging system? My understanding is that this system draws current from the battery. I know first hand that if the battery is in bad condition the system gets quite flakey, but I don't know if exposure to high amperage will mess it up. Ed

I don't know nuthin bout no science, but the instructions that have come with every battery charger I've ever owned said, in bold print, to never try to start the vehicle with the charger hooked up.

I don't know. And I want to learn about it.
To me, one of the things that is a wild card here, (not counting an over the top high voltage jolt from a crummy battery charger) is that, depending on how a diode is forward or reverse biased, ON-OFF in the rectifier block, most diodes turn on when there is .7v to 1v less or more on either the cathode or the anode. When the diode(s) is (are) reverse biased, it (they) should be off and the battery current can't go backwards into the dyno windings.
Diodes can be activated like an on off switch with only a little .7v drop (loss) across it.
So if one side is very low like a dead battery, and the other side is back fed or something with 15v.... then it could be like a flood gate.
But it won't be the voltage that will do the damage, it will be the amount of current that can flow and maybe fry the regulator.
If it's on, there could be a huge amount of current flowing through wires that are built to take only 10-20 amps!
The way the three phases of the dyno and a 6 diode (2 for each phase) rectifier work is very simple and it's easy to see how the high rising AC voltage can ... (when positively going) turn the diode on and the developed high voltage DC is then "steered" by the diodes to the battery and regulated by dumping a bunch through the regulator to keep it at the spec charge voltage..... adding another charge source, (car's alternator and nearly limitless current from a high battery) complicates it.
I simply do not have enough experience with these to have a strong conviction opinion.