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I am new to motorcycles and scooters, although I do have a decent knowledge of cars.

Here is my question. What is the relationship of an alternator to a stator? I do know the function of each in theory, but how do they work togther on a scooter ? -- in this case a 2003 Honda Reflex 250.

The reason I am asking is this. I was told by a mechanic that "the alternator is fine but the stator needs replacement." Is he only referrring to the diode in the case of the alternator? Does his statement make any sense???

Would appreciate your knowledgeable response.

Alternators generate electricity by the same principle as DC generators, namely, when the magnetic field around a conductor changes, a current is induced in the conductor. Typically a rotating magnet called the rotor turns within a stationary set of conductors wound in coils on an iron core, called the stator. The field cuts across the conductors, generating an electrical current, as the mechanical input causes the rotor to turn.

Sounds to me like your mechanic needs some vocabulary lessons.

The stator is the part of the alternator that doesn't turn.

In some cases it's the wire coils that don't turn. In others it's the magnets. I believe that in general on a bikes alternator it is the magnets that turn. But this is not true in 100% of cases.

Okay, here's a schematic from Bike Bandit...
I would say that sev is right, it's the coil that is stationary.
I hope this clears it up a bit....

Usually in bikes the magnets turn and the coils are stationary. There is no need for brushes with such a system, and the heavy magnets serve as a flywheel. Car alternators are just the opposite.

gulfview wrote:I am new to motorcycles and scooters, although I do have a decent knowledge of cars.Here is my question. What is the relationship of an alternator to a stator? I do know the function of each in theory, but how do they work togther on a scooter ? -- in this case a 2003 Honda Reflex 250.The reason I am asking is this. I was told by a mechanic that "the alternator is fine but the stator needs replacement." Is he only referrring to the diode in the case of the alternator? Does his statement make any sense???Would appreciate your knowledgeable response.

The biggest cause of stator burnout is jumping the battery from a car. I know. I burned out two before I learned the correct way to do it.
The main thing to remember is DO NOT TURN THE CAR ENGINE ON!
The amperage of the car far exceeds that of the bike and that is what burns out the stator.
(Words of wisdom from Bubba )

Bubba wrote:

gulfview wrote:I am new to motorcycles and scooters, although I do have a decent knowledge of cars.Here is my question. What is the relationship of an alternator to a stator? I do know the function of each in theory, but how do they work togther on a scooter ? -- in this case a 2003 Honda Reflex 250.The reason I am asking is this. I was told by a mechanic that "the alternator is fine but the stator needs replacement." Is he only referrring to the diode in the case of the alternator? Does his statement make any sense???Would appreciate your knowledgeable response.

The biggest cause of stator burnout is jumping the battery from a car. I know. I burned out two before I learned the correct way to do it.
The main thing to remember is DO NOT TURN THE CAR ENGINE ON!
The amperage of the car far exceeds that of the bike and that is what burns out the stator.
(Words of wisdom from Bubba )

Yeah, all you really need to do is hook positive to positive and negative to negative... erm

Okay positive on car, then negative on car with the jumpers. Be VERY VERY careful not to cross the other ends of the leads, do NOT let them touch under any circumstances. Then connect the positive jumper to the positive bike battery terminal, finally connect the negative jumper to the negative terminal. You've created one big battery. Now try to start your bike normally.

Disconnect in the opposite order, bike neg, bike pos, car neg, car pos. And you're done.