The Honda Common Service Manual is a 5cm (2") thick book winch contains an enormous amount of data. It explains how bolts work and how (not) to install split pins all the way to measuring crankshaft bearing clearance and back probing PGM-FI connectors and everything in between. It explains the operating principle of drum brakes all the way to up the dual-combined brake system and simple centrifugal scooter clutches till the Honda DCT and that strange hydrostatic transmission that the DN-01 had.