Alternatives to Champion D-9J?

[rapier]

What alternatives are there to this plug, for a 1946 Speeditwin (which lists as original 5MJ)? I used NGK AB-6 variants for all my A-series Johnsons (including the 1929 P-45) and wondered if it’s in the acceptable heat range for the Speeditwin?

[garry-in-michigan]

5MJ = D9J = 508 if you’re sticking with Champion. The Johnson PO uses an R-7 = K60R = 506 . . . 😀

[george-emmanuel]

The NGK plug’s heat range goes down as the number goes up. I started off using AB-6 but went to the AB-7 for my Speedifour, Speeditwin and others.

George

[pm-t2]

I always use the antique plugs whenever I can.

It’s not like they’re hard to find, I just scrounge through everybody else’s garbage

Best,
PM T2

[rapier]

Thanks, much appreciated. Champion hard to find here and I’ve had some failures with near new plugs recently.

[rapier]

Managed to find some K60R plugs on Garry’s recommendation. Thanks again.

[garry-in-michigan]

Champion had a problem in the late `40s and replaced a lot of plugs under warrentee until they discovered the plugs they were replacing were a japanese imitation. They were perfect in every respect except for the poor quality of the tea cup porcelain and rice paper cardboard in the box they came in. You could only see the difference by turning the box inside out. Of course the dealers were warned and the Japanese company sued out of business. They made top quality products until they were absorbed by a European conglomerate. Now I fear that Japanese company may be making Champion plugs once again. Evinrude’s money saving move to outsource parts production torpedoed there quality control and destroyed the company. My motto for outboards; "Fast – Dependable – Cheap; pick any two," . . . 🙄

[rapier]

I did wonder who made them now. Need to go with dependability..otherwise is no fun for anyone.

[Mumbles]

Quality NGK’s will keep your motor happy for a long time.

The following link shows what the Champion D9J’s cross over to:

http://www.sparkplug-crossreference.com … AMP_PN/D9J

[rapier]

Yes, my thoughts too. Thanks for the link.

[Author]

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