Hello, my K1 has only been running on 1 to 3 cylinders for a short time. Sometimes it runs on all four. However, this is only rare. What could this be? (K1, BJ. 1991, 41 Tkm) I have already checked all contacts under the tank. The contacts of the harness are clean. I have already checked the petrol pump. Tank, pump, filter apparently so far in order. (some increase in the amount of water found in the petrol.) The contacts of the ignition coils are clean. I mean, one cylinder is completely suspended, because if it only runs on the last cylinder, then it takes the gas badly, and it works rather as a pump than a 4-cylinder engine. I haven’t checked the condition of the spark plugs yet. The spark plugs are so bomb-proof that I have to think of something to pull off the parts. Who knows this defect and what it is about ? Thank you very much for your support. Schraumix from Munich