[Thomas]

Thank you, Paul, I ordered a NGK B6HS. Cheers, Thomas

[phutton]

The plug specified for the 1937 M9 is a Lodge H14. This is a 14mm x 1/2" (12.7mm) reach plug. It is now unavailable, but the nearest modern equivalent is the NGK B6HS, or Bosch W7AC. Try one and see!

P.

[Thomas]

Well, I had hoped to get these information from those who drive the machines. 

[VicYouel]

I suggest you ask http://www.gsparkplug.com/  they are very helpful. The important thing is to use a plug that does not have built in "suppression" for use with a magneto.

I am sure the forum would like to know how you get on.

Vic

[Thomas]

Hi all!
I am looking for a new spark plug for my 1937 Model 9. In the forum I found information that the NGK AB-7 should be fine. Its thread is 18mm but mine needs 14mm. What plug with14mm thread is recommended?
Cheers, Thomas