One particular of the most prevalent of electric scooter components in need to have of substitution, the CDI module is as crucial to the scooter ignition process as the spark plug. Considered to be an creation of the amazing Nikola Tesla, the Capacitor Discharge Ignition (CDI) is the common method used on most of today’s fuel-powered motor scooters, as well as on numerous bikes, maritime outboards and other small engines. A total CDI module is designed up of a transformer, the charging circuit, the rectifier, a capacitor, and the result in circuit.
How the CDI Module Is effective
The transformer 1st raises the voltage to 400 to 600 volts. Shifting alongside the charging circuit, the electric recent rates the capacitor, with the rectifier stopping the capacitor from discharging ahead of the ignition position. Receiving the triggering signal, the trigger circuit stops charging and will allow the capacitor to discharge to the lower inductance ignition coil. This boosts the initial 400-600 Volt capacitor discharge to as a great deal as 40 kV at the secondary winding, leaping the spark plug gap, and igniting the gasoline/air combination in the cylinder. The charging circuit is then reconnected and resumes charging the capacitor all around once more.
AC or DC?
Most present-day scooters us an alternating recent (AC) program on the other hand the well known KYMCO scooter model takes advantage of direct current (DC). As a consequence, electric scooter pieces for KYMCO machines, such as the CDI module, can often be tricky to locate.
It is normally best to match the engine dimensions to the CDI specifications. A CDI module created for a 50cc motor may possibly perform on a 100cc, 125cc, or 150cc motor, and some are developed to operate in excess of a assortment of motor measurements. Many others even so, will only work for a particular motor displacement. Normally test the technical specs to be confident of finding the proper scooter ignition areas.
2-stroke and 4-stroke Scooter Ignition
The 2-stroke and 4-stroke engines are wholly distinctive, and as a end result, their engines’ ignition timing is fully diverse as perfectly. You can not use a CDI designed for a 2-stroker on a 4-stroke scooter. Conversely, you cannot use a 4-stroke scooter’s CDI on a 2-stroke scooter.
On lots of latest CDIs, the connectors are integral to the unit’s case, forming a plug that snaps straight on to the scooter’s wiring harness. On other designs, the connectors may possibly be positioned on wires, allowing some leeway on specifically where the module is mounted. The skillful mechanic may perhaps shorten or lengthen these wires as needed. The most widespread CDI connector design and style works by using two plugs aspect by facet 1 4-pin plug, and a 2-pin plug. These connectors may well be square, rectangular, or easy spades.
Be aware: Photo illustrations of quite a few CDI connectors can be observed at the internet site listed at the base of this article.
Unrestricted or Restricted?
An unrestricted (or racing) CDI offers the present-day no matter how substantial the motor RPMs go. As the CDI controls the spark plug, the plug will keep on to hearth at significant RPM. For reasons that ought to be noticeable, these CDI models are created for racing use, and are not pretty acceptable for common freeway use. A limited CDI module even so, will halt firing after a pre-set engine RPM is attained. Without existing achieving the spark plug, the engine RPMs sluggish to beneath the pre-set restrict and only then will the CDI resume giving existing to the plug.
When changing a CDI module, or any other scooter ignition or electric powered scooter elements, it is constantly a great strategy to reference your owner’s handbook. If the handbook is shed or normally lacking, several companies and brands have downloadable manuals offered on their sites.