Honda C70 / CL70 / Cub / C70M Passport Minibike 1970–1984 Service Manual OEM (P/N 6117401)

• Covers 1970–1984 Honda C50, C65, S50, S65, and the C70 Passport series (including C50M, C65M, C70M, and CL70 sub-variants).
• Official Honda Motor Co., Ltd. service publication (P/N 6117401).
• Features 44 technical diagrams, 21 specialized service tool references, and 6 engine performance charts.

Component and System Breakdown

When you are tearing down a classic OHC powertrain, guesswork costs time. This OEM reference provides the exact factory specifications needed to maintain and rebuild the Honda 50cc to 70cc motorcycle lineups. It completely details the internal architecture of the four-stroke overhead camshaft engine, power transmission assembly, and lubrication circuit.

Instead of generic overviews, you get granular data on the cylinder head, valve operating mechanism, and the self-adjusting cam chain tensioner. The documentation also covers the right crankcase cover, clutch assembly, and breather components. For chassis work, it maps out the exact construction of the handle, front fork assembly, cushioning, and the specialized braking systems found on the S50 and S65 models.

Working on vintage fuel and electrical systems carries inherent fire and shock risks, so always ensure proper shop ventilation and disconnect the battery before utilizing these schematics for live component testing.

Electrical diagnostics are straightforward with exhaustive factory data on flywheel A.C. generator outputs, ignition coil resistance, selenium rectifier maintenance, and flasher relay circuitry. The fuel section provides a complete breakdown of the downdraft carburetor, detailing the functions of the needle jet, main jet, and float chamber.

To ensure absolute precision during reassembly, the manual includes definitive tolerance charts for piston rings, valve stems, and connecting rod end play. Critical baseline specs are clearly laid out: standard engine compression is 170 psi (12 kg/cm²), intake and exhaust valve clearance is set at 0.002 in (0.05 mm), and the fuel reserve tank holds approximately 0.8 liters.