Stator question

M

Mohsen

Member
Hello all, I left my 2005 Kawa Vulcan 500 for a couple of years outside. TBH I just had too much on my hands and just didn't have time to ride.

The battery was obviously gone and it was hard to start it as well. I drained everything and cleaned the lines and the carbs. I boosted it with an old car battery and it was running like new. However, there was no current coming back to the battery. As soon as I would disconnect the battery, the bike would die.

I started at the stator. It's a three phase stator that seems to pass all the known tests but does not generate any electricity. When I measure ohms across the three wires coming out of the stator I get 0 ohms. When I test across the three yellow wires and the body/ground the circuit is open, no change. But, when I run the bike and measure the voltage across the yellow wires and ground, I get 0 volts AC.

Does anyone know why before I make my bald spot bigger by scratching my head too much? Please and thank you!
 
Mohsen said:
when I run the bike and measure the voltage across the yellow wires and ground, I get 0 volts AC.
Click to expand...
That's a good thing.
Each of those yellow wire is one phase of the three phase system
Measure the AC voltage from yellow wire to yellow wire... that's three times
A/B A/C B/C
You should have more than 60 volts at 3500rpm.
You should have NO continuity from yellow wires to ground.

How do you know "there was no current coming back to the battery" ?
 
The stator circuit is isolated from ground - you SHOULD not get voltage between a single stator wire and ground with the stator unplugged from the rest of the bike ... because at that point, it is an isolated circuit.

If your battery-disconnect test was really a battery-disconnect test, no wonder it stalled. The rest of the charging system depends on having the battery "in the circuit" to maintain a stable voltage.

Let's try this again. Let's start with the DC side of the circuit first.

Have the battery connected, terminals tightened, voltage regulator and stator plugged in, everything as it should be.

First, before doing anything, set your multimeter to measure DC voltage, and tell us what the voltage across the battery terminals is. No booster cables connected.

Now, connect booster cables to some other booster battery (other vehicle NOT running), and tell us what the voltage across the battery terminals is. Engine off.

Then, start the engine. Leave the booster battery connected, hold revs at 3000-ish RPM, and again, tell us what the voltage across the battery terminals is.

Let it run like this for a minute or two.

Then, hold revs at 3000-ish RPM, and disconnect the booster cable positive lead. (Not the bike's battery ... that has to stay in the circuit ... the booster cable.). Tell us what happens. If the engine keeps running (and I betcha it does), tell us what the voltage across the battery terminals is. If the engine stops immediately, tell us that, and tell us what the voltage across the battery terminals is.

Follow those instructions precisely, please.
 
Brian P said:
The stator circuit is isolated from ground - you SHOULD not get voltage between a single stator wire and ground with the stator unplugged from the rest of the bike ... because at that point, it is an isolated circuit.

If your battery-disconnect test was really a battery-disconnect test, no wonder it stalled. The rest of the charging system depends on having the battery "in the circuit" to maintain a stable voltage.

Let's try this again. Let's start with the DC side of the circuit first.

Have the battery connected, terminals tightened, voltage regulator and stator plugged in, everything as it should be.

First, before doing anything, set your multimeter to measure DC voltage, and tell us what the voltage across the battery terminals is. No booster cables connected.

Now, connect booster cables to some other booster battery (other vehicle NOT running), and tell us what the voltage across the battery terminals is. Engine off.

Then, start the engine. Leave the booster battery connected, hold revs at 3000-ish RPM, and again, tell us what the voltage across the battery terminals is.

Let it run like this for a minute or two.

Then, hold revs at 3000-ish RPM, and disconnect the booster cable positive lead. (Not the bike's battery ... that has to stay in the circuit ... the booster cable.). Tell us what happens. If the engine keeps running (and I betcha it does), tell us what the voltage across the battery terminals is. If the engine stops immediately, tell us that, and tell us what the voltage across the battery terminals is.

Follow those instructions precisely, please.
Click to expand...
Does there have to be some battery voltage available to the stator in order to allow it to generate juice?
 
Brian P said:
The stator circuit is isolated from ground - you SHOULD not get voltage between a single stator wire and ground with the stator unplugged from the rest of the bike ... because at that point, it is an isolated circuit.

If your battery-disconnect test was really a battery-disconnect test, no wonder it stalled. The rest of the charging system depends on having the battery "in the circuit" to maintain a stable voltage.

Let's try this again. Let's start with the DC side of the circuit first.

Have the battery connected, terminals tightened, everything as it should be.

First, before doing anything, set your multimeter to measure DC voltage, and tell us what the voltage across the battery terminals is. No booster cables connected.

Now, connect booster cables to some other booster battery (other vehicle NOT running), and tell us what the voltage across the battery terminals is. Engine off.

Then, start the engine. Leave the booster battery connected, hold revs at 3000-ish RPM, and again, tell us what the voltage across the battery terminals is.

Let it run like this for a minute or two.

Then, hold revs at 3000-ish RPM, and disconnect the booster cable positive lead. (Not the bike's battery ... that has to stay in the circuit ... the booster cable.). Tell us what happens. If the engine keeps running (and I betcha it does), tell us what the voltage across the battery terminals is. If the engine stops immediately, tell us that, and tell us what the voltage across the battery terminals is.

Follow those instructions precisely, please.
Click to expand...

I think you guys just solved my problem. I was measuring across the ground and each of the yellow wires, instead of across two of the yellow wires.

You are awesome. Thank you.

It's getting dark, but out of excitement I had to go and prove me wrong!!! you are right. The stator circuit is isolated from ground.

I will do that tomorrow and report back. Thanks again to both of you for the replies.
 
Freddy Fudpucker said:
Does there have to be some battery voltage available to the stator in order to allow it to generate juice?
Click to expand...
Yes, The battery supply about 12 volts to start the engine, which in turn runs the stator. That in turn produces alternate current which is changed to DC by another device to recharge the battery and run lights and so on.
 
The stator as my Freddy Fudpucker (what? that's his name, ma!!!) points out is separate from the ground. It's basically a set of coils put in groups of three that have magnets go around them at the speed of the engine. That movement over the wires creates a current. But the current is AC, think of a sign wave where it goes from one pole to the other, it needs to be converted to DC which is like a straight line. Another device cuts the low ends and spits out a straight line of current at around 13 to 14 volts.
 
You're very welcome although all I did was ask a dumb question. My memory is starting to fail me, I forgot that its a magneto. The AC is converted to DC by a rectumfinder..oops rectifier.
 
Mohsen said:
I mean I will report back with the above data.
Click to expand...
Hi, I have 8 with original battery. 12 with a booster. Both with car off. And I get a consistent 12 at around 60ma when running for five minutes at relatively high rev.

So can be presumptive and say regulator?
 
Mohsen said:
Hi, I have 8 with original battery. 12 with a booster. Both with car off. And I get a consistent 12 at around 60ma when running for five minutes at relatively high rev.

So can be presumptive and say regulator?
Click to expand...
60ma?
 
Was the latter measurement with the booster battery connected or not?

At 8 volts, your battery is dead as a doornail. You could try reviving it with a trickle charger, but it is probably a goner.
 
With a decently charged lead acid battery and a functioning regulator, you should get 12.4 - 12.8 volts at rest (engine not running), 13.5 - 15.3 volts with engine running. If the battery is totally dead, it is possible that it is sucking so much charging current that the regulator cannot bring the voltage up until the battery gets to a decent state of charge. The "60 mA" statement makes no sense. Exactly where was this current measured?
 
I was reading it across the battery, connected to the running bike, but I may have misread it. It's not a digital meter. I agree, the battery is dead. I connected it for a trickle charger that tried to recoindition it first, but I could never get it past 8 volts. I filled it up to the lines with distilled water as well.

So at this point, the stator is good; the battery is dead; and when I disconnect the battery from the system it dies. Is there any other component other than the regulator that could be the culprit?
 
Mohsen said:
I was reading it across the battery, connected to the running bike, but I may have misread it. It's not a digital meter. I agree, the battery is dead. I connected it for a trickle charger that tried to recoindition it first, but I could never get it past 8 volts. I filled it up to the lines with distilled water as well.

So at this point, the stator is good; the battery is dead; and when I disconnect the battery from the system it dies. Is there any other component other than the regulator that could be the culprit?
Click to expand...
The battery is dead, not mostly dead - if its feet were not nailed to the perch it would be pushin' up the daisies.
Until you replace it you're flailing in the breeze.
 
Brian P said:
The stator circuit is isolated from ground - you SHOULD not get voltage between a single stator wire and ground with the stator unplugged from the rest of the bike ... because at that point, it is an isolated circuit.

If your battery-disconnect test was really a battery-disconnect test, no wonder it stalled. The rest of the charging system depends on having the battery "in the circuit" to maintain a stable voltage.

Let's try this again. Let's start with the DC side of the circuit first.

Have the battery connected, terminals tightened, voltage regulator and stator plugged in, everything as it should be.

First, before doing anything, set your multimeter to measure DC voltage, and tell us what the voltage across the battery terminals is. No booster cables connected.

Now, connect booster cables to some other booster battery (other vehicle NOT running), and tell us what the voltage across the battery terminals is. Engine off.

Then, start the engine. Leave the booster battery connected, hold revs at 3000-ish RPM, and again, tell us what the voltage across the battery terminals is.

Let it run like this for a minute or two.

Then, hold revs at 3000-ish RPM, and disconnect the booster cable positive lead. (Not the bike's battery ... that has to stay in the circuit ... the booster cable.). Tell us what happens. If the engine keeps running (and I betcha it does), tell us what the voltage across the battery terminals is. If the engine stops immediately, tell us that, and tell us what the voltage across the battery terminals is.

Follow those instructions precisely, please.
Click to expand...
That is some of the best technical instructions I have ever read.

If all manuals could be written in such plain and easy to read language I would actually read them.

RTFM!!!!!!
 
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