My advice: find someone who knows these bikes, pro or amateur. Most of the professionals are pensionados now. But knowledge of the typical things is crucial. I once was given advice by a Guzzi mec. In itself the advice was OK (generic), it just did not apply to our type of carburetors, I found out later. Someone that is familiar with your bike, can estimate what is likely and what not. It is the same with manuals. Lots of stuf is generic, in other words: copy and paste from other manuals. Many who read them, are so eager to tinker with their bikes that they unscrew things just because it is in the manual, not realising that a professional mec who has seen dozens and dozens of these bikes in his workshop could have told them that he never saw that particular problem occur on a CB550 and also the opposite ofcourse.
