Will the engine still run after disconnecting the battery terminal?

Question

Assuming the motorcycle is in working condition, will the engine still run after I started it and then disconnect one of the battery cables?

My thinking is that once it is up and running (optimal RPM) the alternator should take over and provides electricity to where is needed and also charging the battery. Why removing the battery connector causing it to stop?

2001 Kawasaki Vulcan 750.

Answer 1

DON'T do it! Your bike does not have a magneto like a 2 stroke dirt bike nor does it have a DC generator like old cars. On those two you can, but NEVER on anything with an alternator, i.e. just about anything made after 1962. Here's the short and simple of it. The alternator produced electricity and the amount it produces is determined by the voltage regulator. The voltage regulator determines how much electricity is needed by monitoring the battery voltage. A battery is like a sponge for electricity. When discharged the voltage is low and it's like a light weight, dry sponge and will "soak" up lots of electricity. When it is fully charged, the voltage is higher and it's like a sponge soaked full of water, heavy and unable to soak up more. Try to put too much electricity into a fully charged battery and it gets hot and boils the water out, just like that full sponge dripping out water. When the engine is running and you disconnect the battery, the voltage regulator senses very low, actually no voltage, and tells the alternator to produce as much electricity as it possibably can. Instead of the voltage being regulated at around a maximum 14.7 volts like normal, it shoots up to around 18 volts, all the alternator can produce. That fries bulbs, voltage regulators, ignitors, fuel injection components and so on. Even a totally dead, non-operative junker battery will soak up electricity (unless bone dry)and keep you from frying the electrical system, it just won't hold a charge, just like a bucket with a hole in the bottom.

So don't listen to what others claim to know, no matter what they tell you. I've been around a long time, have worked on just about everything and I actually know mechanical and electrical theory (how and why things work), something a lot of so called mechanics don't.

Answer 2

Why are you disconnecting the battery while the cycle is running in the first place? If you are doing some sort of test on the battery or charging system, that is NOT the way it is done. State your problem or what you think is happening in a question.

Answer 3

This is a bad idea!

It will not idle with no battery, that is normal, also, the battery needs to be charged on a charger. The charging system is not capable of charging the battery from dead, but will maintain it.

You can blow the CDI "testing" that battery that way, it is likely the battery is bad, if it was dead and more than a year old.

You may just have to take it to a shop to be checked, where they know how to.

Answer 4

well on a car if you disconnect the battery terminal, u can cause serious damage to the computer, and damage the alternator by causing a power spike, also if the vehicle shuts off then the alternator might be bad, but doing this either way is a bad idea

Answer 5

As long as your charging system is up to specs your car will continue to run, even at idle. If your alternator is bad than no, your car will stop running as soon as your disconnect the battery.

Answer 6

Really depends on the bike and its electronics. Some bikes have EFI that requires the battery to be operational.

Answer 7

No, it won't even work with carbed bikes, I've tried it. It will run for a little while but run like crap and eventually die

Answer 8

Yes. It does'nt need the battery once it's running

Answer 9

not sure but if you have a vn 750 here is a site that will give you a lot of info and help.
http://autos.groups.yahoo.com/group/VN750/