I just found this thread. I have an Echo 21 which had some sort of custom ignition system added. This has a throttle adjustable advance system, but the wires to the hall sensor cracked. I believe C&H (out of business) sold an ignition system with no auto-advance. The only systems I can now find are auto advance such as RCexel. I did test the engine on gas-glow and I may continue to do that. But I am wondering if there are any non-advance ignitions available these days, so I can use the original thottle advance. I may also remove the throttle advance and use an RCexel.
Anyway it's a cute small engine which will find a home on a plane sometime.[X(]

Rod S