This is a complete base assembly for all 1936-1969 Big Twin Harley magnetos. This base assembly can be used to replace your damaged original unit, or for converting another Harley magneto of the same rotation to a 1936-1969 Big Twin magneto.

Please select the standard Harley base if you are replacing the base assembly on your original harley magneto that has been upgraded with a new neodymium magnet with a 3/8" hex in the bottom. Select the Joe Hunt base assembly, which features a 1/4" longer shaft and spacer that raises the magneto out of the engine case if you are replacing the base on your Joe Hunt magneto

Note: Earlier magnetos utilize a 1/4” hex drive on the bottom of the magnet rotor that is susceptible to breakage and has since been changed to a 3/8” hex, so check your existing magnet first. If your magnet rotor still has the 1/4” drive, you must replace the magnet rotor with a new unit or broach your existing rotor to 3/8”.