The Readspeed 8-stage CDI is one of many advance-retard solutions for the 6-pole Ducati-style stator used on many Lambretta and Vespa electronic ignition systems.
Most of the other systems plug into a pre-existing CDI, but this is an all-in-one solution.
There are 8 maps selected by a rotary switch mounted on the CDI itself. These offer static timing as per stator (Position 0), three different advance maps (Positions 1, 2 ,3) and four more linear maps, each retarded by a further 2 degrees (Positions 4, 5, 6, 7).
The advance maps offer either 5, 7 or 9 degrees of advance in the 2,500 to 4,500 rpm range before retarding back to a linear static setting above 5,000 rpm. While not optimised for any particular engine set-up they might be regarded as a selection of relatively safe maps to boost low-rpm performance on most tuned engines.
The linear retard settings are potentially useful should you encounter engine problems while riding; poor quality fuel, overheating or maybe a fractured exhaust. By selecting one of the static retard settings (for example going from 16 to 14 degrees static) then you effectively have a low-power ‘limp mode’ for getting home.
We have one of these CDI’s fitted to a TS1 with no problems.
There are now several more adjustable or fully programmable solutions on the market that may be tailored more accurately for an individual engine but this really requires dyno testing. As a simpler all-in-one solution the Readspeed CDI is decent value at £85 and offers sensible settings to boost performance with minimal risk.
Note: it is vital to set the ignition timing with a strobe to establish your base timing for position ‘0’.
- Easy to adjust
- does not require pre-advancing of the stator plate (unlike many plug-in solutions)
- Several linear retard maps allow for ‘safe mode’ riding in the event of fuel problems
- Single bolt fixing
- wire-to-wire connections not ideal
- more sensitive to pick-up height on stator plate than some CDIs
You can purchase the Readspeed 8-stage CDI here.