124 pages, 78 black & white illustrations, size 5.5 x 8.5 inches. Originally published under the title The Second Book of the BSA Twins by A.G. Lupton, this book is one of The Motorcyclist's Library series published in the USA by Floyd Clymer by arrangement with the original publishers Pitman Ltd. of London, England. It includes complete technical data, service and maintenance information and detailed instructions for the repair and overhaul of the major mechanical and electrical components for A50 & A65 BSA twin cylinder models from 1962 through 1969. There is adequate detailed text and diagrams to assist in major refurbishing such as an engine rebuild or even a complete renovation. Applicable to all 500cc & 650cc BSA unit construction A50 & A65 twins including the Royal Star, Thunderbolt, Wasp, Cyclone, Hornet, Lightning & Spitfire. This publication has been out-of-print and unavailable for many years and is becoming increasingly more difficult to find on the secondary market and we are pleased to be able to offer this reproduction as a service to all BSA enthusiasts worldwide.