Electronic ignition systems

Pros and Cons

Electronic ignition systems are reliable and maintenance free so they always provide a good reliable spark, they will reduce vibration when used on a twin because the sparks will be exactly 180 degrees apart, which they rarely are with a non-electronic system. The cost varies but they are typically the same price or cheaper than reconditioning a magneto. Most retain the original appearance of the machine with perhaps the odd extra wire. On some models not all the standard parts for the original ignition system are available and electronic ignition will get the bike running.

The main argument against electronic ignition systems is that the reliance on modern technology goes against the principles of riding an old machine. In the old days, when life was simple, the machinery was simple as well and when it broke down, which happened a lot more than it does now; it was highly likely that it could be fixed at the side of the road. Modern technology is incredibly reliable but when it does break down, there is little chance of fixing it at the side of the road and usually the only course of action is to replace expensive components or throw the whole thing away. It is possible to carry spare parts with you on a long journey and many do but this does increase the cost. Depending on the machine, space will have to be found for an ignition coil and switch, there is extra wiring and a reliance on the dynamo or alternator to supply the power. On a non-magneto equipped machine the cost is much higher than repairing the standard system.

In summary, electronic ignition is worthwhile on a multi-cylinder machine as it will improve the running and although very unlikely to give trouble, it is usually not possible to repair it except by replacement.

How does it work?

There are several types of systems but the essential components do the same job. Firstly there is a switch or trigger that replaces the contact set, the purpose of which is to send a signal to the ‘black box’ so that the electronics know the position of the piston and therefore when to fire the plug. The electronics that control the ignition are contained in a small box, usually but not always black in colour, and will be connected to the trigger, a power supply via a switch and to the high tension coil(s). The more basic systems retain the old advance and retard mechanisim, whether manual or automatic whilst the more sophisticated types use electronics to provide the advance and do away with the original advance and retard mechanisim.

The trigger can be optical or magnetic but will involve a rotor of some sort that will break a beam or induce a current in a small coil. This is usually mounted in place of the old contact breaker.

Availabilty

Some kits include HT coil(s), some are extra but are listed below. None of the kits include a switch, sometimes the original kill switch, where fitted, can be used. An easy solution is to use a dip switch mounted on the handlebars.

Fieldmaster (KH) and Huntmaster (FH) Twins with K2F magneto

We stock 2 systems. The trigger is either fitted inside the magneto thus retaining the original appearance or in a replacement housing,

IGN-10             Complete kit except for switch, includes twin lead coil (45077T-6), trigger fits inside magneto for 6 Volt system
IGN-11             Complete kit except for switch, includes twin lead coil (45077T-12), trigger fits inside magneto for 12 Volt system

IGN-13             Complete kit except for switch and coil, fits inside IGN-12 housing, 6 or 12 Volt depending on coil
IGN-12             Housing for IGN-13, replaces magneto
45077T-6          Twin HT lead coil, 6 Volt for IGN-13
45077T-12        Twin HT lead coil, 12 Volt for IGN-13

Ariel Square Four

The 1936-48 models with magnetos have always been troublesome due to the large amounts of heat generated by the engine, this is one bike that really does need an electronic system. Everyone that I know that uses these bikes has converted to electronic. The kit is similar to the one used on the twins where the trigger fits inside the magneto.

1936-48 models with MN1E magneto
IGN-14             Complete kit except for switch and coil, trigger fits inside magneto for 6 or 12 Volt system. This kit retains the manual advance

1949-58 models with DKX4A distributor.
IGN-15             Complete kit except for switch and coil, trigger fits inside distributor; uses standard 6 or 12 Volt coil. This kit retains the mechanical advance

IGN-16 is the negative earth version

45124A             6 Volt HT coil, for IGN-14 and IGN-15. Same as original 1949-58 type
45124B             12 Volt HT coil, for IGN-14 and IGN-15. Same as original 1949-58 type
45124C             Clamp for large HT coil 45124, Omega type
45124D             Clamp for large HT coil 45124, Triumph type