Bill Jepson has sent TWO messages that are relevant to using this unit
as a basis for a Cheap Chinese (CC) Magneto.  (Note the new thread
name.)

----------------------------
Paul,

I think it's funny I haven't seen that mag since 1976! As a young (very)
mechanic that exact same looking mag was used on the Kawasaki G31M. Kawasaki's
first effort into a 125cc motorcross bike. The early ones had a points cam on
top of the permanent magnet rotor. The funny part was if you revved the motor
past 1500RPM you could hold the points open and the magnetic pulse would still
fire the plug. Sounds like it's right up your street for things that need
little to keep running. The later ones used a tiny box and a hall effect pickup
to trigger. A true magneto though as the bikes had no battery at all.



Bill Jepson
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Paul,

Unless I miss my guess I believe you will still need to have
an external high tension coil.  That unit is the crankshaft attached
unit for a SINGLE cylinder Honda copy laydown 50 or 90cc engine. The
little box is attached to the small trigger coil at about 3:00o'clock
in the picture, and it is a points replacement.

Bill Jepson
----------------------------

Since the unit has been around for 30+ years, I feel better about its
reliability.  For firing plugs in a two-rotor engine we could graft
two units together 180 degrees apart around a single magnet rotor.

I'd still think about building/buying a high-quality igniter, though,
unless we test the included igniter for hundreds of hours.

Triggering still needs further examination.  I am guessing that the
trigger fires 3 times per revolution (3 magnets = three cycles/pulses).

I probably mistranslated the Chinglish phrase "high pressure bag end"
to mean "high voltage spark plug".  It most likely means "high voltage
ignition coil".

Again, I have included a picture of the $45 unit.  Also included below
is Paul's schematic from a Mariner CDI system.  On the schematic,
ignore the bottom "Lighting Coil" portion.

For slow speed cranking issues, we could parallel power the igniter
input with the battery (through a diode or bridge rectifier).  This
would ensure that the igniter has plenty of power even when magneto
juice is feeble.

Of course the (induced) trigger signal needs to be adequate to fire
the igniter's SCR.

I'm feeling better about this as a pursuit for a rotary engine magneto
option.  It's something that the conservative Lycoming crowd will
understand and respect, as opposed to the ECU ignition that most
rotards are using.  :)

-Vince Orton


Vince.

Chinglish.  Yes good one:)  Now you know the adventure I've had for 30
years trying to decipher Japlish in technical product manuals. The $45
sale price worries me.  Too cheap.  This is probably a rip off of the
rip off with a production price under $10.00.  That means inferior
magnetic steel and not neo dynium boron magnets. Just for your
information.  Japanese factories work on a 15% margin for mass produced
goods.  Sometimes less but that is in cases where the factory is part of
a conglomerate or association.  Toyota and Denso relationship for
instance.  Toyota  squeezes all their down-line suppliers HARD.

China factories out the door margins are lower because the middle men are
many and they squeeze the production people something HARDER. Ultimately
the line workers carry the brunt of the pain and are lucky if they get
paid regularly.

BTW I thought perhaps a magento like this could be used as one of two
power sources (the other  multiple CD) that would Y into the leading
spark plugs.  The timing advance issue concerns me however.  Perhaps the
magneto charging an ultra-capacitor that is regulated to fire the plug
in concert with  the other ignition system might work.

One half rpms at the distributor housing rpms aren't such an issue
because this unit wouldn't be needed to actually start the engine.

Doug in Japan