Hi

c_moore

I am using with success high voltage coils from Honda Transalp , TEC brand, all the modern japanese motorcycles small displacement are with CDI and the coils perform well.
If you have no problem with a bit of weight go to HV motorcycle coil.
Also you can use recycled HV coils from Byke repair shops.
I have bought a new and make test and after when all runs properly I switched to recycled to avoid mistakes and focusing only the coil.
In the back of coil you will find two tabs the green is positive and black is negative and must be connected to the negative of battery.
I am tested many hours in a test stand in a 38 cc Homelite chainsaw engine and flown a Weedeater 18 cc with the Tec coil, no problems, make a shield in the HV cable and things go well.
Have luck
Jose