Quote:
Originally Posted by tortoise
Curious about your vendor resource, since there appears to be an abundance of bogus performance components.
Somewhat puzzling how a performance AC-CDI advances the timing firing curve, due to the fixed positions of the pickup coil and outer flywheel trigger magnet. Since there are two flywheel triggered impulses to the CDI to fire the sparkplug during a 4-stroke cycle (one is typically wasted), perhaps a performance CDI circuit is actually delaying the sparkplug impulses so the effect is an advanced firing curve.
This vendor offers an original type GY6 AC-CDI and ignition coil for around $20 shipped. |
If I were to guess it is able to time the milliseconds between the spark signal to calculate RPM and then is able to advance the timing to the RPM. Since it would spark before the next spark signal it would just use that signal to verify the RPM and then recalculate the next spark timing.
I picked up this performance coil and CDI for 12.99 shipped! Actually I purchased two, one for me and one for my son. We have not installed his yet though. The package actually arrived 7 days earlier than the earliest estimated date listed in the add.
http://www.ebay.com/itm/171385631946 If you look around the picture shown on this ebay listing is the same used on many domestic listings that are many more dollars.
Since I installed my CDI/coil my scooter seems to idle smoother with a little bit higher RPM, by ear. I am thinking that it is the coil giving me a better burn. Could be a bit more advanced, not sure though. I was really surprised that the motor seemed smoother at higher RPM too. The advance must be making the motor operate more efficiently, therefore making it run smoother. I have not run past 45MPH yet. When I pin it at 40 it feels about the same as the old CDI, but once it started moving it picked up much faster. I contribute that to the fact that the advance does not drop off, such as in a car when throttle is applied. Pretty happy with the results though.