James, sounds like a good idea ... & sample of glow in:
http://www.giangrandi.ch/electronics/neon/lamps.html
What resistance would you suggest?
Might be easy to enclose in a ballpoint pen case.
alp

On Sat, 23 Dec 2006 07:32:03 GMT, James Sweet
wrote:

edolo wrote:
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


Wouldn't a neon glow lamp be a better choice than an LED?