Hey Greg,
quote gjonz:
What kind of modern spark plugs should I use?
Thx!
Greg
What, if anything, was in the hole when you got the motor?
I’m sure someone who knows will eventually show-up with data, but if not, you’ll just have to pin down the basics (thread size / pitch / reach) and pick a plug in a middling heat range – like an NGK 6 or 7 or a Champion 6 and try it.
On these old motors, just about anything (heat range-wise) should be OK for initial shake-down runs in a tank, etc.