Spark plug Champion N4C
Set of 2
Triumph 350, 500, 650 with Alloy head. BSA Twins with Alloy head. Ajs/Matchless Twins and Singles with Alloy head. Many other makes with long reach Alloy head.
BSA A7/A10 - Aloy Head
all AJS/Matchless
Alloy Head Model
1950-1966
Thread: 14mm
=NGK B6ES.B5ES
AJS 33, 16C Experts
Ariel Leader, Arrow, Arrow Super Sport, Golden Arrow, Arrow 200
BSA A7SS, A10RGS, A10RR, A10SR, A50, A50C, A50CC, A65, A65LC, A65R, A65T, B32 Alloy Head, B40SS90, Victor B44R, B44SS, Victor B44ET, B44GP, B44VS, C15SS80, Bantam D10, D14/4, D14/4S
Matchless 1964 onwards, G3C Maestro, G3C Trials, G80 Major, G12 Majestic
Norton 650 Dominator, 650 Mercury, 1964 onwards all other models
Royal Enfield 736cc Interceptor
Triumph TR5 Trophy Alloy, TR5A, 6T Alloy, T100, T100S, T100T, T110 Alloy, 21 5 TA, T100A, TR7A, TR25, Tiger 90, TR6, T120 pre 1968, 1968 onwards
Velocette: MSS 500cc Alloy, Viper Sports, Viper Clubman, Venom Special, Venom Sports