A friend of mine that helped me fix up my old BMW has one of these, and we used it extensively as a reference, so I had to buy one. He has a couple of airheads himself and knows much about the general ideas behind the engine, but he does not have the same model as mine so we used this book for some of the specifications. I tend to like this book more than the Haynes manual, which my friend has as well. NOTE: I have read on some of the discussion forums that both the Clymer's and Haynes have a few errors/type-o's in them, and it is good to check multiple sources for any major job you have to do.