Hi, all.
In preparing my scooter for experiments, I plan on replacing the rather weak OEM ignition coil with a Pertronix Flame-Thrower HV 60,000 Volt 1.5 Ohm coil, transmitting the spark to the plug via a Magnecor R-100 CN ignition wire. They should be delivered within the week.
The spark plug is a Pulstar HE1HT9, which I'm really impressed with.
My old coil is wired like the attached file. You'll note there's a snubber diode to prevent high secondary coil voltage from bleeding back through the common connection with the primary coil and blowing out the ECU's CDI.
The red wire comes straight from the battery's (+) terminal, the yellow/black wire goes to the CDI (which is actually more like a set of solid-state Kettering ignition points than an actual higher-voltage (200-400 volts) CDI setup).
The new coil doesn't have that diode in it, so high voltage can (read: will) bleed back and destroy the CDI if I try to run it without some isolation.
So... what circuitry should I use to isolate the CDI from the coil, while still allowing switching on/off at up to about 12,000 RPM?
It'd be a huge plus if it allowed the tachometer to continue working... the tachometer taps off that same yellow/black wire. Apparently it just reads each time the 12V drops to zero and converts that to RPM.
In preparing my scooter for experiments, I plan on replacing the rather weak OEM ignition coil with a Pertronix Flame-Thrower HV 60,000 Volt 1.5 Ohm coil, transmitting the spark to the plug via a Magnecor R-100 CN ignition wire. They should be delivered within the week.
The spark plug is a Pulstar HE1HT9, which I'm really impressed with.
My old coil is wired like the attached file. You'll note there's a snubber diode to prevent high secondary coil voltage from bleeding back through the common connection with the primary coil and blowing out the ECU's CDI.
The red wire comes straight from the battery's (+) terminal, the yellow/black wire goes to the CDI (which is actually more like a set of solid-state Kettering ignition points than an actual higher-voltage (200-400 volts) CDI setup).
The new coil doesn't have that diode in it, so high voltage can (read: will) bleed back and destroy the CDI if I try to run it without some isolation.
So... what circuitry should I use to isolate the CDI from the coil, while still allowing switching on/off at up to about 12,000 RPM?
It'd be a huge plus if it allowed the tachometer to continue working... the tachometer taps off that same yellow/black wire. Apparently it just reads each time the 12V drops to zero and converts that to RPM.