Electrics & Ignition

Services for Classic bike Ignition & Electrical systems

  • LUCAS K2F & K2FC (twins) reconditioning
  • LUCAS M01 (singles) reconditioning
  • Electronic Ignition conversion kits
  • LUCAS E3L dynamo reconditioning
  • Electronic Regulators AC & DC
  • Wiring & Fault finding


We specialise in renovating the LUCAS K2F and K2FC magneto fitted to twins and the LUCAS M01 Magneto (Magdyno) fitted to the single-cylinder engines.

The most common problem with original magnetos is failure once hot. The engine will start from cold, then run for a short while, and a misfire will develop, causing the engine to stop.

However, once the engine is cold again, it will restart. Usually, this is caused due to a breakdown in the insulation of the condenser or the armature windings themselves.


When we undertake the renovation of these magnetos, we examine the following:-

• Mechanical - Bearings, insulation, washers and shimming the armature

• Electrical - Armature windings, Condenser, Slip ring, Points and Bushes

• Magnetic - Check magnetism and Remagnetise magneto body

• Ignition - Check Spark strength, Spark timing and stability


We use the CRYPTON MAGMASTER (from the 1950s) to do a comprehensive testing programme on each magneto we rebuild.

This allows us to make slight adjustments to the magneto to achieve the best constant and accurately timed spark that the magneto can produce.


The final 20-minute hot running test program includes:-

• Checking the normal spark HT Voltage;

• Checking the maximum available spark HT Voltage;

• Checking the ignition timing stability over-rev range;

• Checking the ignition timing for correct timing angle (for most twins, this is 180 degrees);


By performing this test, we can be confident that the magneto you fit your engine will be at peak performance and will remain reliable for years to come

Send your magneto to us, and we will test it to assess its’ faults and provide an estimate for the work required.

Our 2-year guarantee backs each renovated magneto.


Electronic Ignition Conversions for Magneto

We offer conversion kits for the K2F and the M01 magnetos. The kits are based on the Boyer Micropower ignition system with our own sensor unit. This unit will fit in place of the armature in the magneto housing, thus retaining the original appearance of the magneto. The ignition advance/ retard is controlled by the electronics in the ignition box and fires via a small single (or dual) output coil. The low power consumption of the ignition system makes it ideal for bikes with a dynamo charging system with limited power available.



At SRM, we specialise in the renovation of these particular models of LUCAS dynamos.

In the 1940s, the LUCAS E3H (40 Watt) unit was used extensively on various British single-cylinder engines, later replaced by the more powerful LUCAS E3L (60 Watt).

British twins such as the BSA A10, TRIUMPH T100, T110 and NORTON DOMINATOR used the E3L dynamo.

The design of this dynamo is the same throughout the range, but different driveshafts are used for different models.

Each dynamo is tested on the CRYPTON ELECTRICAL TEST BENCH to determine its condition, and an estimate of the cost to renovate the unit is produced.

If the dynamo were fully restored a new armature and field coil would be fitted together with new bearings. The outer body would be Nickel plated, and the alloy ends bead blasted. New brushes would be fitted, and then the dynamo would be thoroughly tested.

Firstly the dynamo is wired for a ‘motor’ test - this runs the dynamo as a motor, the motoring speed is checked, as is the polarity and rotation. This test also polarises the magnetic field in the field coil core;

The dynamo is then fitted to the CRYPTON ELECTRICAL TEST BENCH to simulate being fitted to the engine. This test confirms the dynamo will charge when fitted to the engine and in the correct polarity for the earthing system on the bike.

A 2-year guarantee backs each Renovated dynamo.


6-volt to 12-volt conversions

The faster a dynamo turns, the more voltage it produces - the voltage regulator sets the system voltage. So the simple conversion is to fit an electronic regulator box in place of the original electromechanical device. This does mean that the cut in rpm is a little higher to reach the 12 volts; however, this is not a problem.

For the BSA A7 &A10 SRM, produce a Dynamo belt drive kit to replace the dynamo chain. This will also ‘gear up’ the dynamo drive to speed up the dynamo rpm concerning the crankshaft.


For Technical details, Availability and Pricing, please get in touch with us.