>I do not understand the spark out of the engine and possibly none inside
>unless the cranking compression is making it harder to actually arc.
>Maybe someone else understands it.

Bernie, Voltage requirement is directly proportional to pressure. I'm not the EE in the group but I'm sure there are tables for it somewhere. There is something else to look for guys especially on plugs that have been cleaned. Look for a dark line on the insulator. This often requires a magnifier. This is a carbon path that has been developed on the plug while firing a flooded or very rich mixture. It can be VERY hard to clean off. You can sometimes even see the spark jumping down that path. Even if you have a spark there it usually won't ignite the charge in the combustion chamber. If you see a line of any kind on the porcelain disguard the plug. The path makes it easier to foul the plug later.

Bill Jepson