WD spark plugs

[jerkus730]

What is the correct spark plugs for a magneto WD?
 

[old]

I run NGK3112 in my WD45 and have had very good luck with them so they should be fine in your WD
 

[Skyhighballoon(MO)]

I thought the older short cylinder heads on the WD's took 3/8 reach plugs and the taller heads on the WD45 and D17's took 3/4 reach plugs.
 

[DrAllis]

After the last 50 or 60 years, who knows. From the factory, 3/8" reach spark plugs were used on all WD45's and early D-17's prior to chassis s/n 24001. Any D-17 after that and all 170-175's were always 3/4" reach plugs. HOWEVER, if you replaced a tall cylinder head with a new one from A-C, you were given the newest head, which meant 3/4" reach plugs. So, one must look over the depth of the threads if there's a question.
 

[jerkus730]

It's the stock head, I was told it should have non resistor plugs. I don't even know if that is correct.
 

[old]

With a mag you don't want resister type plugs.