1 of the most frequent of electrical scooter areas in want of substitution, the CDI module is as crucial to the scooter ignition procedure as the spark plug. Assumed to be an invention of the excellent Nikola Tesla, the Capacitor Discharge Ignition (CDI) is the standard process used on most of present-day gas-powered motor scooters, as nicely as on a lot of bikes, marine outboards and other little engines. A comprehensive CDI module is created up of a transformer, the charging circuit, the rectifier, a capacitor, and the bring about circuit.
How the CDI Module Functions
The transformer very first raises the voltage to 400 to 600 volts. Moving along the charging circuit, the electrical recent expenses the capacitor, with the rectifier blocking the capacitor from discharging in advance of the ignition issue. Acquiring the triggering sign, the bring about circuit stops charging and lets the capacitor to discharge to the low inductance ignition coil. This increases the initial 400-600 Volt capacitor discharge to as a lot as 40 kV at the secondary winding, leaping the spark plug gap, and igniting the gas/air combination in the cylinder. The charging circuit is then reconnected and resumes charging the capacitor all about once more.
AC or DC?
Most present scooters us an alternating recent (AC) process nonetheless the well-liked KYMCO scooter brand works by using immediate present (DC). As a consequence, electrical scooter elements for KYMCO equipment, which includes the CDI module, can from time to time be hard to come across.
Engine Measurement
It is normally finest to match the engine dimensions to the CDI specs. A CDI module created for a 50cc engine may possibly operate on a 100cc, 125cc, or 150cc motor, and some are made to function about a range of engine dimensions. Others nevertheless, will only function for a particular motor displacement. Generally check out the specifications to be certain of receiving the suitable scooter ignition sections.
2-stroke and 4-stroke Scooter Ignition
The 2-stroke and 4-stroke engines are absolutely distinct, and as a end result, their engines’ ignition timing is thoroughly distinctive as effectively. You are not able to use a CDI manufactured for a 2-stroker on a 4-stroke scooter. Conversely, you cannot use a 4-stroke scooter’s CDI on a 2-stroke scooter.
Connectors
On a lot of latest CDIs, the connectors are integral to the unit’s scenario, forming a plug that snaps immediately on to the scooter’s wiring harness. On other styles, the connectors may possibly be located on wires, enabling some leeway on particularly in which the module is mounted. The skillful mechanic may perhaps shorten or lengthen these wires as needed. The most common CDI connector style makes use of two plugs aspect by aspect a person 4-pin plug, and a 2-pin plug. These connectors may perhaps be sq., rectangular, or uncomplicated spades.
Be aware: Photo illustrations of quite a few CDI connectors can be viewed at the internet site mentioned at the base of this short article.
Unrestricted or Restricted?
An unrestricted (or racing) CDI offers the present-day no matter how large the motor RPMs go. As the CDI controls the spark plug, the plug will carry on to fireplace at substantial RPM. For factors that ought to be noticeable, these CDI units are designed for racing use, and are not extremely acceptable for standard highway use. A limited CDI module nonetheless, will prevent firing when a pre-established motor RPM is attained. With out existing achieving the spark plug, the engine RPMs slow to underneath the pre-set limit and only then will the CDI resume supplying existing to the plug.
When replacing a CDI module, or any other scooter ignition or electric scooter elements, it is constantly a good strategy to reference your owner’s guide. If the manual is lost or or else missing, many suppliers and brand names have downloadable manuals accessible on their websites.
