I do not have a service manual and understand that stator outputs vary a good bit by model. I have an 03 ultra classic putting out 12 volts ac on idle and 16 volts ac at 2000. I'm thinking it should be a good bit more. I know the numbers sound typical for dc but this is on ac and at the disconnected first terminal from stator. Also this is not 3 stage that I was expecting with twin cam model. What should outputs read.

 

my 01 was aprox. 21vac at idle. I you do get a new one, and this what I did, get the cycle electric here phase kit.

 

From the manual for a Sportster the output of the stator with the engine running at 2000 rpm is 40-56 volts AC (approximately 20-28 volts AC per 1000 rpm). The test is conducted with the regulator disconnected.

 

Voltage regulator disconnected, what is the resistance of the stator wires across them, since this will tell you if your have melted wires (coatings melted off) together or not, without having to pull the magneto.

Hence when a stator burns up, it not always that that the wires crack apart to lose continuity through the wires, but loose thier protective outer coating from too high of heat through the wires to create shorts between the wires on coils, to not produce a electric field on those coils isntead.




As for resistances on the stator with voltage regulator disconnected.

• 22 amp system produces about 0.2 to 0.4 ohms
• 32 amp system produces about 0.1 to 0.2 ohms
• 45 amp system produces about 0.1 to 0.2 ohms

As for Ac voltage with the regulator disconnected.

• 22 amp system produces about 19-26 VAC per 1,000 rpm
• 32 amp system produces about 16-20 VAC per 1,000 rpm
• 45 amp system produces about 19-26 VAC per 1,000 rpm

 

A lot of good information Dano. So into the stator and found a match to your photo. Thanks

 

Thanks lunchbox, found a bad stator

 

Thanks Andy, found a bad stator

 

Just a fyi, but what kills a stator, is running a battery that is on it last leg/should have been replaced a long time ago that does not come up to a full charge.

Hence is not a problem after you start the bike and the charging system charges up the battery in a few mins of the stator charge being pulled full tilt , but when the battery does not get to the point that the voltage regulator backs off on what is pulling down from the stator/the stator is being pulled down full charge the entire ride to melt the wire coatings instead.

So really, need to work from the battery back, through the main breaker and wiring/ground points, to make sure that the voltage regulator can see the real charge of the battery once it does charge back up, so it not pulling full charge from the stator the entire time the motor is running instead. Most of the time is just the battery not able to charge all the way back up, but as stated, corroded contact points on the charging system, or even a main breaker that is internal corridor that does not allow the voltage regulator to see the full charge state of the battery so it not trying to keep putting out full amperage all the time.

 

The stator and rotor put out full power all the time.....excess is shunted to ground through the regulator.

The only way to control output of the alternator is to use an electromagnet rotor, which gets power from the voltage regulator to increase or decrease the power of the magnet.

Harleys use a permanent magnet system.