Bonneville America Forums Forums Technical Forums General Tech Battery Question

If the connections to the battery come loose while riding, does the bike cut out or doesn't it matter once the bike is running?

I think it quits.

not sure, Why

You opened the circuit, a bike will run on a dead battery, but will not run or start if the circuit is open i.e. discounting the battery.

If your alternator is charging it will continue to run.

Like they said, it'll keep running. However most modern car makers don't recommend it as it can damage the computer, so probably not the best idea to try it unless you feel like forking out for a new CDI.

No battery no place to dump the excess voltage. The alternator's diodes will burn up if you disconnect the battery. Vehicles that had generators could run without the battery and start without the battery. Our high voltage ignition systems need a battery to start, a reasonable charged one at that.

Don't quote me. This is experience from a 51 chevy perspective.

Thanks for the input. The reason I asked was because I took the bike to Fla. and it kept cutting out on me but never stalled. As I loaded it on the trailer to head back to the blizzard in N.Y. I noticed the neg. connection to the battery was loose. Now I won't have a chance to ride again untill the spring so I don't know if that was the problem or if I should be looking for something else. 45,000 miles with no troubles until now. I guess it could be a number of things. I do know that it isn't gas or vent related.

If the clamps come loose while riding the bike will keep running. She just wont start again if you turn her off.
I know this from experience.

If the cable rattles about and makes/breaks contact, the voltage spikes will cause the ignition computer to reset. This makes the engine run badly while it is happening, then it will run better at times when the cable stays in contact.

If the connection breaks completely, it depends on the design. Breaker point ignition will run just fine if the voltage pulses coming from the charging system are timed to match the point timing. Electronic ignition may run OK if it has a voltage smoothing circuit.
The super gotcha is the type of regulator you have. Older BMWs had a car type alternator that was regulated by varying the field current. Some motorcycles have a series regulator that works much like better regulated power supplies. Either of these will usually work well enough with a dead or disconnected battery.
If it has a shunt regulator (diverts current to ground, controlling alternator output by overloading it), which is common on Japanese designs, the lack of a good battery to increase the load results in a voltage runaway that will fry all your electronics and lights.

Happened to me once on the interstate. It was really freaky to loose power at 60mph. The bike acted like it was out of fuel. Once I tightened the terminal, all was well.

Hi...I've been having problems with my bike cutting out...backfiring both thru the exhaust and carb. I've had it to the dealer 3 times...still not fixed!! I have it stored away for the winter, but I have just noticed that my tach isn't mounted firmly to the tank, which would enable water to get in under there where all the connections are!! I'll try some contact cleaner and electrolytic gel to seal things up...I hope it works!!