Thanks Triton for your explanation, my Cub still runs on the original ignition on top of the engine, with an electronic rectifier and a large capicitoe to replace the battery. 
Cold pushstart and with a warm engine no problems kicking the engine and I'm still pleased with it.  
I'm worried at the moment that there's something wrong inside the engine and I placed a topic about that, golden glow oil. 
I have not got any replies yet !