In looking to order spark plugs for my 1936 Muncie Neptune OB34A, 4 hp twin,
I found a chart that suggested using Auto-lite 386 (18mm plugs).
They are listed as "Resistor" type spark plugs.
What’s your thoughts as far as using resistor type spark plugs in a magneto
system?
Thanks, TG
That’s the trouble with spark plug charts. They’ll tell you to use anything that fits the hole. As a general rule, resistor plugs are to be avoided in outboards, with a few exceptions. And I don’t think that Muncie would be one of them.
I Have Champion #516 or D-16 in mine. Set at 0.025". I was recommended those Autolight 386’s some time back and bought a dozen of them. They don’t work on any of our old motors.
The Champion spark plug list shows the 6M plug. The modern plug number for the 6M is a D14 #514 gaped at .025 , the D16 #516 is a hotter heat range, possibly too hot and may cause problems if used.