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Made in the USA
Manufactured by AUTOLITE (4275)


Designed for a sharper, leaner spark with tapered nickel/chrome alloy tip and copper center electrod

Below is a cross reference list of spark plugs for use in most Harley models. While the Motor Company only recommends use of their original equipment Harley brand spark plugs, the other brands often exceed original specification and will not void your warranty. NGK and Autolite, among others, have always been a preferred performance plug for Harley motorcycles. In addition, it is often more convenient to use aftermarket spark plugs aside from the enhanced performance. All spark plugs listed meet or exceed manufacturer specifications.

NOTE: Iridium plugs should only be used with electronic ignitions, not for use with point ignitions.


Panhead/Shovelhead 1947-1974: H-D Standard 4R or 4R5 / H-D Gold 4R5G / Screamin’ Eagle SH12S / Autolite 4275 / NGK R5670-5 (2298) / Denso Iridium IWF22

Spark Plug Autolite Au-4275 (48-72 Big Twin)

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