You want one of those little neon panel lights. Add a fairly high
value resistor and you have a spark detector.

edolo wrote:
Thanks all! Yes you can build a circuit to take even 50,000 volts,
but that's beside the point. Sure I could spend four hundred a buy
the real thing, but where is the fun in that - & besides, I was
thinking of taking the four hundred with me when I go. cheers!!!

On Wed, 20 Dec 2006 16:23:03 -0500, Gene Kearns
wrote:

On Tue, 19 Dec 2006 18:32:06 GMT, edolo penned the following well
considered thoughts to the readers of rec.boats:

Have a couple of manual testers, but would like to build an LED
in-line unit to test spark on two, four, and six cylinder outboard
motors. Anyone have a design or know where such a unit can be obtain?
tks, alp

I remember seeing these things 40 years ago. IIRC.... think neon....
Anyway, the parts might be difficult to obtain. See Mouser and the
like.....