There are a bewildering amount of ignitions on the market, usually divided into two groups.
Static - It is pretty simple really, fixed timing is just that, once you set your ignition timing it does not move or adjust.
Variable - Ignition timing can automatically advance or retard, which can give more power, especially lower down the rev range. It can also make your engine cleaner running and even improve fuel efficiency. Then usually the system automatically retards with rising revs, meaning a cooler, safer and better engine. There are a lot of benefits to running advance / retard ignition systems with more powerful and exotic engines. Standard engines of course still benefit greatly as well.
The static kits are mostly based on "Indian" or "Vespa" style systems, all use the same family of components, some of course better quality then others. Here lies the problem, with the vast amount of manufacturers / modifiers, it can sometimes be difficult to separate the good from the bad. For example when looking at bolt on variable timings, they will rely heavily on getting the correct exact signal from the pick up. Use a lower quality pick up, and things go wrong. The same applies to how well the Pick up, stator coil, and CDI, work together, get it wrong and failures will occur.
Having said all that, some of these systems can work well, but if your looking at the higher quality end of these, and then adding on variable / programmable timing, you would be wiser to buy one of the specific pre made kits.
The second group of kits have taken more modern systems, and manufactured them for the Lambretta. Many are / or were based on the original Varitronic kit.
Below is a brief description of what each kit does. Non of the kits are full D.C, instead they have battery charging capabilities.
There are a good number of manufactures of Indian Electronic systems, so you need to rely on your supplier selling you a good one. On the whole, such systems all use similar components, some much better then others, and some well lets say make a good door stop.
The major advantage of such systems is they are cheap, and easy to obtain spares and have them repaired.
Timing is fixed, and the cooling from the fins is fine. Good for those on a budget, or more of a standard type engine. The kit we sell is a basic but quality system, no frills, but they work
The Varitronic was the first production electronic kit with variable timing which wasn't based on the aforementioned Indian kits. Instead, existing quality modern electrics from a modern scooter were adapted, and perfected for use on a Lambretta. In fact the Varitronic lead the way, many others have copied it and made their own systems.
As revs start to rise, the Varitronic will automatically retard the ignition timing around 8 degrees, giving great levels of power and safety. Once retarded, the Varitronic does not retard higher with revs, meaning once set and checked, it wont change no matter how high you rev.
The first, and still the only kit made for every Lambretta engine, from the 1950's C, LC, D, LD, E, F, TV1, Li/TV/SX Lui and J 50cc machines and all Vega, Cometa, J100 (Cento) & J125 models.
For machines fitted with GP type crank shafts, you can choose the flywheel weight options, the lighter option is ideal for reed motors, or those wanting a more responsive throttle. The heavier kit is better suited to piston port engines and more touring engines
It is capable of running AC or DC from the same kit.
Cambridge Lambretta offer the P.T. Works programmable mapping system, for even more configurable options.
The original Casatronic was a direct copy of the Varitronic. However they have stopped producing this now, and only produce the current kit which is made by Ducati.
A simple to use item, three variations are produced, road Li/TV/SX and Road GP type - both of which have fixed timing, sport - which has variable timing. The third version; the race, has extreme retard timings which are only any good on complete race engines, or the high revving SSR SRT kits. The Casatronic has multiple lighting coils for more stable lighting at tick over speed.
Good quality kit, is individually tested before it leaves the Ducati factory. Whilst it is the most expensive electronic kit on the market, buyers love its fit and forget simplicity.
The only down side we can throw at an otherwise great kit, is Casa do not allow the user to set or alter a desired timing.