I hope somecan help me. We have a 100cc King engine which, although a few years old, had never been started until today.
After adjusting the H&L settings we have managed to get the engine to start and tick over up to about ¼ throttle nicely.
The engine has been fitted after market with a CH Electronics ignition system, with mechanical advance retard linked to the throttle. i.e a throttle coupled spark advance (TCSA) system

When the throttle is advanced above ¼ it starts to hunt and will not hold its rpm.

any suggestions on whether its the ignition set up or the engine itself and how to go about identifying it?

cheers