[SEL] 2 ignition questions - FM 1.5

[bill at antique-engines.com]

Here's an image of what I've got - where would you place the diode?

http://antique-engines.com/images/fm-ignition.JPG

The wood block is the same size as the Bosch mag, I drilled down through
it, aimed a wire at the pin on the cam when the piston was just prior to
TDC, can adjust by bending the wire which is bronze brazing rod - it's
tough, flexible/springy but can be bent to shape. The block clamps in
exactly how the mag did. I put a terminal on the block on the same screw
that holds the trigger wire in place in its hole.
The image link above is how it's wired now (and the engine runs like a
champ, meaning all prior issues with missing, etc. was ignition related -
which is what I suspected all these years but never took time to prove.)

Bill

>
>>
>> 2. To get the engine running for Waukee without the mag working, I made
>> a
>> wood block to fit in place of the mag and rigged a wire through the
>> block to
>> trip on the same pin that tripped the mag finger. This triggers one of
>> those
>> "buzz coils" made using a car coil and a "kit" (turns a car coil into a
>> buzz
>> coil). Makes for a real hot buzz coil setup.
>> Anyway, it's wires like any other buzz coil setup, the system grounds
>> when
>> the wire contacts the roller/pin on the cam, however, I note that sparks
>> fly
>> from the wire and cam pin.
>> I wonder - can that arcing be reduced or taken care of using a
>> condensor?
>> Would it still function?
>> It sort of is a concern as should a bit of gas be in the area,
>> well............
> Bill, you can try a "clamping diode".  Find a diode, old alternator or
> Radio Shack. Install it between the wire and ground, use a test light to
> figure which way to put it. The diode should not flow current when in the
> circuit, won't light the light, reverse it if it does. The sparks are
> caused by reverse emf which is current flowing back the other way, if you
> have + hooked to the coil, the reverse emf will be coming back negative.
> The diode will flow the negative current to ground and prevent sparking.
> J.B. Castagnos
> Belle Rose, LA
>