Viola: Big Fat Spark!

Finally figured out the problem with the electrical setup - and managed to get spark!

The problem turned out to be that the mounting bolt on this Chinese coil was actually grounding it to the frame!

After an afternoon of testing, I found a big clue in that I was only seeing 0.3 volts between the open points (where there should have been at least 6).  Folks on the S90 group confirmed that something was shorting.  I started to work backwards from the points, checking each connection, but got all the way back to the coil and was still seeing the voltage drop.  Finally realized that it was the coil mount, and confirmed that when I found continuity between the bolt and the wires.

So I hung the coil from the frame so it wasn't touching anything.  With that done, I was getting 6v at the points.  And with that, I got spark!

For reference, here's how everything was wired.

Condenser
- long green wire connects out to points
- short blue wire to the coil

Coil
- green wire to the condenser
- black wire to battery positive
- spark plug body ground to engine block

Battery
- positive lead to coil's black power wire
- negative ground to engine block


Also, these were the components:
- the NGK plug
- the Daiichi points and condenser
- the #1 chinese coil

The final setup that worked.

Daiichi points and condenser.

DON'T leave the points connected with the battery wired up.  It will overheat the coil and crack the plastic.

Old (bottom) and new points.  These appear to be Nippondenso style points.

New points mounted.

And finally some new old parts from eBay.  A points cover, baseplate and head cover for Viola so that I can clean hers up and use them for the model top end.