1967 GE spark plugs

[pan620]

Any advice of what spark plug to use in a 67 GE motor? Thanks Dave

[Sargehere]

If it's an 18mm plughole, start with a Champion D-16 or equivalent. Won't hurt it at all.

[Rubone]

Standard H-D plug was a 3-4. The equivalent is a Champion J12Y. The standard iron heads on a '67 are 14mm, unless they have been changed to earlier aluminum heads which are 18mm size. #2 H-D were used on city traffic engines to prevent fouling on continued low speed use.

[pan620]

The threads are 14mm. so I will go with the 3-4 H-D plugs thanks for the help.

[Rubone]

Pan620,
Make sure you use the short reach plugs. H-D also sold a long reach 3-4 which will not work in your GE.

[Chris Haynes]

Champion UJ12Y work well in my Servi-car.

[jaybee47]

Just acquired a '66 GE police trike.
Its spark plugs are marked Champion J16C.
Good to use?
What spark plug would be recommended for occasional short distance riding?
Thank you.