"Terry Spragg" wrote in message
> It's a neon bulb with a resistor in series.
Are you familiar with the S-80 and M-80 specifically?
The reason I ask is that there is also a type of timing light that uses a
neon bulb in series with the spark wire. You pull the spark plug wire off
the plug, stick one wire of the light into the bulb and the other wire onto
the spark plug. The ignition spark then flows through the neon bulb to the
spark plug. There is no series resistor for the neon bulb.
30 years ago these type of timing lights were popular because they were so
much cheaper than the inductive pickup types. Since then, the advancements
in electronics have made the inductive pickup units so much cheaper that the
neon lights don't make a lot of sense, especially because they were so dim.
The neon lights still have one feature that would make them useful: they
don't require any power source. This is really helpful on a small engine,
such as a small outboard, that does not have an electrical system to power
the inductive pickup units.
Rod McInnis >> Stay informed about: neon test light question.