'79 KZ650 charging/electrical problems are driving me crazy

at idle 1200 rpm ac voltage ranges from 21.0 to 24.5 volts
at 4k it sits at 72.0 to 73.3. clymer calls for 75.0 ac.

this voltage is about the same on both stators i have. and both are 2 wires. i have another one here but it is a 3 wire.

jim

Listen, don't be revving that thing up so much; it's old and needs to be babied!

Damn hot rodders

oh thats right 4000 rpm on a 78 bike.

kinda like sex for a 60 year old

should not be done....... oh but what a way to go

I would be surprised to see 75 VAC at 4K rpm... would think it would be ~40-50 VAC but if that is what they expect, that is what they expect. Main thing is that all possible tests are more or less the same.

wiredgeorge wrote:

I would be surprised to see 75 VAC at 4K rpm... would think it would be ~40-50 VAC but if that is what they expect, that is what they expect. Main thing is that all possible tests are more or less the same.

So, does that mean the stator's output is ok? If so, what test(s) do you suggest next?

What do you think about Jim's suspicions about the magnet?

wiredgeorge wrote:

I would be surprised to see 75 VAC at 4K rpm... would think it would be ~40-50 VAC but if that is what they expect, that is what they expect. Main thing is that all possible tests are more or less the same.

Clymer calls for 75VAC, I got 72-73. Geaorge, do you think that rules the stator out?

If so, what do you suggest I look at next?

ok all you kz wizards. this one is about to drive me to pulling hair.

have blown 2 regulators (i think) neither was new. one was 4 wire one was 5 wire.

test results,
yellow wires output 75 v ac after changing rotor.

black/yellow wire (which appears to be a ground) 140 mv

white/red wire shows battery voltage.

brown wire (for the 5 wire if im getting this correct) also shows battery voltage.

something here just doesnt seem right but im missing it.

please what am i missing/overlooking?

dont want to put another regulator in unless everything is where it is supposed to be.

also are these regulators like on a car, must disconnect battery before connections are made?

thanks for any assist.

jim (the rattled one)

You may have a parasitic draw, if so it needs to be fixed first as indicated by WG.

I agree.

If your parasitic draw is significant enough, it may overcome the charging system on your bike.

Leave the bike overnight without the charger in place. Measure battery voltage at the terminals. Remove the negative cable wait 10 minutes and remeasure with the negative cable removed, report results here.

Have your battery load tested, or crank the starter and measure what voltage the battery drops to. Report info here.

When servicing your vehicle, it is best to remove the negative cable to prevent accidental shock. It serves no other purpose.

update,
using both meter inline for draw test and a light bulb, same config, no power unless turning on the key. turn off and light goes out.

battery status, on charger for 3 days so full charge, off now for 2 days, 12.9 volts and drops to 10.6 while cranking with headlamp on.

Have you considered the ignition switch may be shorted internally. Do you have the wiring diagram so we can puzzle this out with you? I still think a pinched/burned wire is to blame.

good possibility and yes i have wiring diagram.

thanks
jim

Motorcycle switches can fail internally for several reasons: 1. Having a mass of keys on a key ring in the ignition switch causing wear internally. 2. Vibration from the normal operation of the engine(things buzz and shake at different frequencies,mirrors blur,pegs hum and shake etc).