The Rupert Ratio
BSA Unit Singles Manual
C15, B40, B25, B44, B50
BCS Book # 214-9818
"Armed with this book even the least experienced 'spannner man' has a reasonable hope of not only being able to dismantle and rebuild a BSA Unit Single, but of making it go better and more reliably than even BSA thought possible! This book quite literally takes the BSA (and Triumph) Unit Single engine apart. All the weak points and many of the strengths of the Unit Single lie exposed and the remedies carefully explained. Everything from tuning the carburettor to a complete engine rebuild is described in great detail with a host of illustrations to make the job easier. There are tuning tips to enable the owner to improve the performance of his machine and complete specifications to ensure a knowledge of what was originally fitted. Unit Single Owners everywhere will find this book to be a gold mine of useful advice."