Ignition system

Magneto Repairs

We repair your old unit rather than exchanging it for a reconditioned item as costs can vary and it means that you will keep your original unit. The unit is stripped down, cleaned, plated and painted before being assembled with the necessary new parts which will always be a new or re-wound armature, bearings and brushes. Finally the unit is tested before being returned to you. All units are fully guaranteed, not just for 1 year but consideration will be taken into account of the mileage covered, mind you I cannot remember the last time we had one returned as faulty. Always tell us which bike the unit is to be fitted to and the polarity if it is a dynamo. Standard is negative earth up to about 1949 and positive earth after that. See the technical pages on the web site for details of 12 volt conversions and electronic voltage regulators. Average prices are given in the price list using the following codes.

RES 116                 To fully re-conditioned your magneto
RES 116A               To supply a re-conditioned magneto

40 or 60 Watt, that is the question; the answer is 1 field coil screw is 40 Watt, 2 denotes 60 Watt. The direction of rotation of a component is always as viewed from the drive end.

See introductory notes under the 40A Dynamo heading above for general information and notes about overhauls. It is possible for the amateur to recondition the magneto but a special puller is required to remove the bearing inner races, which has to be done in order to shim the armature. See the end of this section for electronic ignition systems.

1936-49            Singles      MO1            MO = Magdyno with face cam, 1 cylinder with short 40 Watt dynamo

1950-58            Singles      MOIL           MO = Magdyno with face cam, 1 cylinder with long 60 Watt dynamo

1955-57            HS MK I     KNR1          K = lightweight unit, N=45mm spindle height, Racing, 1 cylinder

1948-57            KH/FH        K2F             K = lightweight unit, 2 cylinder, Flange mounted,

1936                 4F              MSL1S        MSL = Magdyno with 3rd brush dynamo

1937-48            4G              MN1E          MN = Magdyno with ring cam, 1E = 4 cylinder machines

1949-58            MK I/II        DKX4A        = Distributor, KX, 4 cylinder, Automatic advance

Many early KH models were fitted with BTH magnetos.