Voltage meter flickering?

My voltage meter on my 1980 KZ750 LTD is flickering any time the motor is above idle. At idle, the needle is below 6 volts. Also the battery is discharging at idle, but I know on the Honda Nighthawks this was normal, not sure on these bikes though. Is this a common problem or some loose connector or do I have more serious problems? I'm not too great at diagnosing charging systems.

GingerKid wrote:

My voltage meter on my 1980 KZ750 LTD is flickering any time the motor is above idle. At idle, the needle is below 6 volts. Also the battery is discharging at idle, but I know on the Honda Nighthawks this was normal, not sure on these bikes though. Is this a common problem or some loose connector or do I have more serious problems? I'm not too great at diagnosing charging systems.

This is the reason we use resistor spark plugs (or resistor wires or resistor caps). It RF interference on the meter at certain RPMs. If you are already running resistor wires etc, then your meter just may be too sensitive. You may need to get a cheap analog meter. They can be had for about $10 or so from China on ebay. They are crap, but for simple DC voltage readings they should be ok. The part that usually fails on the meter is the test leads. Get better leads if you can.

I'm not sure if I have resistors on the plugs or wires, any simply way to check that? I know the previous owner put nkg wires on the bike, so he might've gotten the wrong ones.

I should've been more specific on the voltage meter I was referring to. The one that is flickering is the one that is part of my instrument panel. I haven't put my multimeter on the bike while revving since I haven't figured out how to hold them on the posts while opening the throttle.

I just found out today that I'm only running on 3 cylinders, but that may have been because I knocked something loose while working on the carbs earlier.

If it's the voltmeter on the bike, then it's probably a loose wire somewhere, as you said. The one on the bike is analog.

The filebase here probably has the wiring diagram so you can trace it down, unless it is internal to the voltmeter unit, that is.

kzrider.com/index.php?option=com_docman&...w&gid=142&Itemid=108

Is it the lights that are flickering or is the voltage needle flicking?

If it's the lights, trace the blue blue/red wire.
If it's the actual meter, then it's a loose connection on the brown wire, or it may be the alternator or rectifier/regulator etc. are actually faulty. You'll need a test meter to find out.

Ok thanks, hopefully I'll have a chance to look into it over the next few days.

EDIT: is it normal for the bike to discharge slowly at idle?