Manufactured by NGK (7634)
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.
 
EVO 1340 80”: H-D Standard 5R6A / H-D Gold 5R6AG / H-D Platinum 5R6APP / Screamin’ Eagle EVS13S / ACCEL 2410A / AC Delco R44NS / Autolite 4265 / Autolite Iridium XS65 / Autolite Platinum AP4265DP2 / Bosch Platinum WR8DP / Champion RN12YC / Denso Iridium IW16 / NGK - Cooler - BPR5ES-11 (7634) / NGK - Hotter - BPR4ES-11 (4224) / NGK Iridium BPR5EIX-11 (2115) / NGK Platinum BPR5EVX11 / Splitfire SF6D / E3 E3.34
 
Shovelhead 1975-1981: H-D Standard 5R6A / H-D Gold 5R6AG / H-D Platinum 5R6APP / Screamin’ Eagle EVS13S / ACCEL 2410A / AC Delco 44NS/44XLS / Autolite 4265 / Autolite Platinum AP4265DP2 / Bosch Platinum WR8DC4 / Champion RN12YC / Denso Iridium IW16 / NGK BPR5ES-11 (7634) / NGK Iridium BPR5EIX-11 / Splitfire SF426E