I had such poor experiences with 'professional' motorcycle mechanics in my early years on bikes that I gave up on Japanese bikes for decades, instead running MZ's and teaching myself how to maintain them as I went along. The money I saved I used to 8nvest in decent tools, some of which I still have all these years later.
Even now, I still don't allow anyone else to work on a bike I'm going to be riding, and always give 2nd hand bikes a thorough going over. I'm in a bit of a quandary with the little 125 though as it came with a Honda service plan when I bought it 2nd hand. I'm struggling between my naturally parsimonious nature which is forcing me to let the Honda dealer do the next service, and my dread of them touching it!