Vekenti

Hello, I recently acquired 2 O&R 23s for a very good deal. I've been flying glow engines in my planes for about a year and a half now, but wanted to get into gas and these little engines seemed like a great start. If I get them running good I might even put them into my RC DC-3 :). I already have both engines taken apart and the internals are quite clean. Pleasantly surprised for engines that can be as old or older than myself. I'm going to mount a carb on both to convert them to R/C. I'm not really sure on how these engines really work, specifically the spark/ignition part. I know back in their days there were ignition coils to produce the spark. Those small coils seem few and far between now so I have been trying to find alternatives. Has anyone used CDI on these old sparkies? I have bought an used CDI unit to test it out. What else can I use to run ignition with these engines? Any help would be appreciated, Noah.