'93 FXR Charging Question. Help !

[Hoople]

I am not saying your stator is bad & you should replace it but it is very difficult to determine if a stator is 100% good while it is still installed in the bike. Just a few shorted turns of wire can not be measured with a standard ohm meter. Even holding the stator in your hand has it's limitations. The magnet wire insulation is only a few thousands of an inch thick. Even performing a load test on the stator is not 100% proof positive. It throws the odds way in your favor, but nothing is a 100% sure thing when it comes to stators. Usually discoloration of a coil will give it away.

But there is a good side. A shorted voltage regulator will almost always take out a perfectly good stator. But a shorted stator has a very small chance of destroying a perfectly good voltage regulator. It is much more risky to only replace the stator and use the old VR. If you do, you must monitor the current draw of the stator when you start the engine.

There is much less risk in replacing just the VR while using the original stator.
All this applies mostly to single phase systems. It's different w/ 3 phase.

Changing the circuit breaker is good. At least there should not be too much of a voltage drop between the battery and alternator.

 

[kenshapiro2002]

Thanks Hoople...probably doing the new VR today.

 

[TQuentin1]

Only measured the stator output as I worked the throttle. How do you do it under load? Dyno?

No fluid in my primary!

I hear you, but if the stator is putting out 20-60 volts (not under load) wouldn't a good VR be doing better than a static 12.5 under the same conditions?

1. Have to "pin through" the wire and measure while the plug is connected and the stator is under load to the VR.

2. Do you have a dry (belt driven) primary?

3. No. I had a burnt stator that showed appropriate Vac under no load conditions (about 20 Vac/1000 rpm), but would not put out juice under load. Opened up the primary and voila! Burnt stator.

TQ

 

[kenshapiro2002]

1. Have to "pin through" the wire and measure while the plug is connected and the stator is under load to the VR.

2. Do you have a dry (belt driven) primary?

3. No. I had a burnt stator that showed appropriate Vac under no load conditions (about 20 Vac/1000 rpm), but would not put out juice under load. Opened up the primary and voila! Burnt stator.

TQ

1. When you say "pin through the wire" do you mean the two wires between the stator and the VR?

2.Yes.

3. OK...thanks.

 

[TQuentin1]

1. When you say "pin through the wire" do you mean the two wires between the stator and the VR?

Right. Before starting the engine, poke a pin or probe into the wire insulators, start the engine and measure the Vac with the stator connected to the VR as the rpm increases (be careful not to get bit by the exposed pins or probes!!). You may find that you do not get appropriate increase which will point to your stator. If it does increase appropriately, then I would swap out the VR.

TQ

 

[Jack Klarich]

1. Have to "pin through" the wire and measure while the plug is connected and the stator is under load to the VR.

2. Do you have a dry (belt driven) primary?

3. No. I had a burnt stator that showed appropriate Vac under no load conditions (about 20 Vac/1000 rpm), but would not put out juice under load. Opened up the primary and voila! Burnt stator.

TQ

1. When you say "pin through the wire" do you mean the two wires between the stator and the VR?

2.Yes.

3. OK...thanks.

Wondering if the end play on the crank is taking out the alternator? I had a stroker I had worked on a while back drove me crazy eating alternators, til one day I checked the end play sure enough TOO much plus getting the belt TOO tight was a problem JMO

 

[kenshapiro2002]

OK...good news , though I know I won't be believing it for some time now. The new VR is in and she's putting out 13.5-14.5 at the battery. All is well, but I'm guessing if my stator was the cause of my VR going bad it will eat this one too?

 

[TQuentin1]

OK...good news , though I know I won't be believing it for some time now. The new VR is in and she's putting out 13.5-14.5 at the battery. All is well, but I'm guessing if my stator was the cause of my VR going bad it will eat this one too?

Might, but since you had tested the stator and did not find any shorts, it was probably just the VR all along. No harm in checking the Vac under load though. Might just be for peace of mind!!

TQ

 

[kenshapiro2002]

Might, but since you had tested the stator and did not find any shorts, it was probably just the VR all along. No harm in checking the Vac under load though. Might just be for peace of mind!!

TQ

Nah...ignorance is bliss. I'm going to assume everything is fine. If it goes south again, I'll just do the stator again. In fact, I might just refresh my charging system every few weeks or so. Actually don't feel like poking holes in my nice new wires. Also enjoying, no matter how short lived perhaps, the feeling that all is well in the world of this magnificent FXR. Thanks for all your help...for everybody's.

 

[kenshapiro2002]

100 miles and all is well (fingers crossed).