while were on the subject of Alternators, I have one of those BF20's an 4stroke outboard motor made by Honda, its 20hp, with an 6 amp alternator stock. Its a pull start model with a tiller handle. Only weighs like 106 lbs dry weight.(yes, this should be in the remote living section, the engine has like a 4-star emissions-rating)
Anyhow, its the type with 4 magnets in a radial configuration built into the flywheel. the stock stator is basically a simple single laminated bar with a coil surrounding it. it is configured to reach at least 2 magnets in the flywheel per angular orientation.
The exciter coil for the ignition magneto(on my engine) is basically of the same configuration.
Now, the 12amp stator(that comes on the electric start engines) is in a radial configuration(with 12 poles, but im sure one of the poles is used for the exciter coil, but im not exactly sure), using a 12magnet radial flywheel(it's different than 4 magnet fly wheel that I have). This is different from the charging system that I have, as the exciter coil is not built into the the stator, it is stand alone, and my flywhell has only 4 magnets(there barrium ferrite).
I have obtained a L shaped stator for the charging system(charge coil), it will work with the 4 magnet flywheel that I have stock(my engine is not electric start). But will produce 10-amps, using a 4 magnet flywheel.
The problem is that the boss's cast into the engine block to support the exciter coil and alternator coil(stator) will not accept the L shaped charge coil, since it has a different bolt pattern. I bought this thing as an upgrade kit for my engine.
Although, my engine block does have the cast-in boss's to accept both the 12 amp radial charge coil, and the separate exciter and 6 amp charge coil, the L shaped 10-amp charge coil will not align itself on-center with any of the boss's, with relation to the flywheel.
Here's the catch,
Both the stand-alone exciter coil and 10-amp L shaped charge coil, have proper diameter to fit under the flywheel that I have, it has four magnets. Im relatively confident things are correct in terms of generation capacity, and with the phases and what-not. Also the regulator/diode bridge that I have can handle atleast 12 amps.
The reason I dont just go ahead and use the radial stator, is that, it causes a different waveform to come from the built in exiter coil, which is in-turn dependant on the 12 magnet flywheel, and the connections for the ECM, will not match-up between the electric start versions and non-electric start ones. So to make the flux paths correct for the radial stator using 12 magnets, it opens a whole can of worms.
Do I need an adaptor?
JW