Hi, been out with the plane today, but the engine is still having the mis fire problems. The spring was missing that grounded the cap, so i put an earth strap from the engine to the outside of the metal outer sheaf of the plug lead. This have cured the interferace probblem but the motor is still mis firing. I has moved the mixture in and out and apart from the normal poor running being over rich or lean the miss continues. I have moved the timing but again the engine runs the same. It does feel sounds like the ingnition system is playing up. I dont know what else to do except by a new igniton system, but dont want to until i know for a fact that my ignition is broken.

Any other help information most welcome