I bought this book after noticing that one review complained about the examples being old.
However, I was extremely satisfied with this book, and I concluded that all the other 2-stroke books I know, are outdated by this book some 20 years.
I bought this book together with "The high performance two-stroke engine" by John Dixon.
Graham Bell's book is "the book" for those interested in tuning.
The information on the latest engines is usually known by a few people, each of them usually knows about one specific engine, and the tricks are kept as a secret. Therefore no one should expect to find a book with very recent examples.