Hello dear people, Hab’ a nice black .. I just wanted to have “slow idle” and the training drive was too high for me. The problems started with it.. If the engine is cold, needs too much “choke” after the engine start. I have to let it pull otherwise the engine shuts down. I hear a few “close” back from the spark plug. If I would go off, the engine stutters or coughs back in the exhaust… I have to change the spark plug back – because very black is and drive ic h further. Without problems. I should notice that the training drive is not set down enough. In this case the engine takes a lot of time to start driving and the problems are stronger. I didn’t know why the exhaust was shooting back. I was already in a factory. The mechanic found nothing special. He changed 3 Gumi ring because it had gone a bit kaput. And the light was dead at the front too. (since then I did oh twice) Why does the engine d he spark plugs kaput? And why is there such a big difference between cold and warm driving? Thanks Akujka