Why adjust BMW motorcycle valves?
Valve adjustment is one of the most misunderstood maintenance items on the BMW. You are really performing a diagnostic function. For example, the engine will run very well with a setting of exactly zero clearance up to double the spec. With zero clearance, the valves will open a bit more and allow more fuel into the combustion chamber and that will make more hp, but you may not be able to measure it with a dyno. Really wide spacing will make more noise and not allow as much fuel into the combustion chamber, but again, you probably can’t measure it. The wider clearance will make more noise. The main reason to do the valve adjustment is to check for a change in settings from the previous time. If one or more valves are more than .001″ off of where they were last set, you better make a notation in your log book. If a dozen people set your valves, they would each do it slightly differently. Which method is right? All are probably right. The important thing is to do it exactly the same from