no spark in 47 cub

[jakieboy]

I have a 1947 farmall cub that has a J4 magneto that was running when I got it. It sat for a few months before I went to start it again. Now I have no spark at the plugs. I thought it maybe the coil, so I replaced it along with new points, plugs, condenser, rotor and cap and wires. still no spark. Checked to see if terminal to the magneto to the kill switch might be grounded somehow it is completely insulated. What am I missing? It ran before just fine.
Additionally, I can't figure out how the voltage (6 volts) gets to the magneto? the only wire going to the magneto comes from a switch that has one (1) terminal and one wire. This cub is 6 volt system with positive ground. How does the voltage get to the coil to be stepped up? I'm very confused please help.

 

[LouNY]

A magneto generates it own electricity, that wire is coming from the mag to the switch, when you activate that switch it grounds the mag out, try disconnecting that wire and see if you have spark
when it is grounded it will shut it down,

 

[CincyFlyer]

A magneto generates it own electricity, that wire is coming from the mag to the switch, when you activate that switch it grounds the mag out, try disconnecting that wire and see if you have spark
when it is grounded it will shut it down,

^^This^^. Think of a magneto as a self-contained ignition system; you can even pull it off of the engine and test it on the bench. Small airplanes (all of those burning gasoline) have two of them, and two spark plugs per cylinder, thus isolating ignition from the rest of the electrical functions. Most magnetos have the ignition coil built into the system; if yours is external, time to check the generating coil in the magneto itself.