Manufactured by NGK SPARK PLUGS (2633)
Superior construction for serious power
NGK makes plugs for almost every application and riding style
Versatile plugs with wide operating heat ranges prevent fouling from running too cool and preignition from running too hot
Features high alumina ceramics for improved heat dissipation and electrical insulation, deep-seated copper core for a wider heat range and a nickel alloy tip for longer life
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.

XL Sportster 1000: H-D Standard 4R5 / H-D Gold 4R5G / H-D Platinum XL10S / Screamin’ Eagle 2413 / AC Delco 42F/42-6FS / Autolite 4123 / Bosch Platinum W5AC / Champion RL82YC / Denso Iridium IWF22 / NGK BPR6HS-10 (2633) / Splitfire SF412C