Regular ignition servicing is one of the most effective maintenance tasks on the MGB, worn points, a deteriorated condenser, and a tired cap and rotor are responsible for more cases of poor cold starting, rough idling, and flat throttle response than any other single cause. Renewing all the wear items together ensures a consistent result. Ignition service kits are available for four applications. The kit for cars to 1967 suits the 25D4 side-entry distributor on early 3-synchro cars.
The kit for 1967 to 1974 suits the 25D4 top-entry on 4-synchro chrome bumper cars. The kit for 1974 to 1980 suits the 45D4 on rubber bumper cars. A separate kit covers 45D4 distributors fitted with sliding points, which use a different contact set to the standard pivoting type, confirm which is fitted before ordering. Each kit supplies cap, rotor, points, and condenser matched to the distributor type.
Renewing the full set rather than individual items as they fail is the recommended approach, a new set of points alongside an aged condenser will not perform as well as a complete renewal, and the cost difference is modest.