Honda C70 / CL70 / Cub / C70M Passport Minibike 1970–1984 Service Manual OEM (P/N 6204003)

• Model coverage: Honda C50, C50M, C50MK1, S50, C65, C65M, S65, CL70, C70, and C70M, together with separate 1980–1982 C70 Passport shop-manual coverage and a 1981 C70 Passport parts catalog.
• Engine and drivetrain repair: Covers engine removal and installation, OHC top-end overhaul, piston and cylinder inspection, lubrication and oil-pump service, cam-chain tensioner, clutch, gearshift linkage, transmission and crankshaft, and kick-starter work.
• Chassis repair: Details steering-head service, bottom-link and telescopic front forks, rear suspension, wheels and brakes, swingarm, drive chain, controls, air cleaner, frame, and exhaust inspection.
• Fuel and electrical diagnosis: Covers carburetor circuits and adjustment, ignition timing and contact-breaker checks, flywheel A.C. generator and charging tests, battery and rectifier work, electric starter, switches, lighting, horn, and fault isolation.
• Factory reference material: Provides a dedicated 1982 C70 addendum, nine model/year wiring diagrams, five engine-performance curves and five running-performance charts for the C50, C65, C65M, S50, and S65, plus troubleshooting, torque tables, inspection limits, clearances, and electrical test data.
• Tools and parts identification: Includes a 21-item legacy special-tool chart, additional C70 tool references, and 36 exploded parts diagrams with corresponding Honda part-number lists.

Engine, Transmission, and Internal Service

This 441-page PDF set combines two Honda Motor Co., Ltd. shop manuals with a separate 1981 C70 Passport parts catalog. The earlier volume covers the listed 50cc, 65cc, and 70cc models. The later manual is specifically marked for the 1980–1982 C70 Passport, carries Honda publication code 6117401, and contains a separately structured 1982 addendum.

The legacy manual explains the four-stroke OHC engine from oil circulation and cylinder-head construction through the valve mechanism, camshaft, piston and rings, crankshaft, transmission, clutch, and breather. Its CL70/C70/C70M supplement uses the CL70 as the basic model and calls out C70 and C70M differences where required. This distinguishes the different clutch, transmission, front-suspension, starting, and ignition arrangements before repair information is selected. The supplement relies on the 50/65 base sections, which are included in the same volume.

The later Passport manual separates lubrication, fuel system, engine removal and installation, cylinder-head and valve work, cylinder and piston service, clutch, gearshift linkage, transmission and crankshaft, and cam-chain tensioner repair into their own chapters. It identifies the factory procedures for removal, disassembly, inspection, replacement, reassembly, adjustment, and final checks. Model-identification pages show where to locate the frame number, engine number, VIN label, and carburetor ID before choosing parts or specifications.

Chassis, Fuel, and Electrical Systems

Chassis coverage extends beyond routine adjustment. The manuals address the C-model bottom-link front end and the CL70 telescopic fork, plus steering-head service, rear shocks, swingarm, wheels, hubs, brakes, drive chain, controls, cables, and exhaust. Separate S50/S65 braking information and C70 front- and rear-suspension chapters help match the repair procedure to the correct chassis layout.

Fuel-system material covers carburetor circuits and component function, float-level inspection, jet and needle service, choke operation, air-cleaner work, and year-specific adjustment data. Electrical repair coverage includes generator output and charging tests, ignition-coil and contact-breaker checks, spark advance, battery and selenium-rectifier service on the earlier models, the C70 electric starter, switches, lighting, turn signals, horn, and fault isolation. The 1982 addendum updates engine, chassis, fuel, charging, ignition, and starter information, with separate troubleshooting and wiring coverage.

Diagrams, Tools, and Shop Notes

Representative illustrations include the self-adjusting cam-chain tensioner and oil-damping circuit, engine lubrication routes, clutch and transmission section views, and C70 cable and wiring-harness routing. Full wiring diagrams cover the C50/C65 family, CL70, C70, and C70M General Export and U.S.A. configurations; the separate 1982 C70 diagram brings the set to nine. The parts catalog contributes 36 exploded assemblies, including the carburetor, top end, clutch, oil pump, transmission, starter, suspension, brakes, frame, lighting, and wiring harness.

The legacy supplement identifies Tool Set No. 07900-1186000 for the CL70, C70, and C70M, shared with the C65/S65. Listed examples include drive-sprocket holder 07922-0400000, flywheel puller 07933-0010000, valve-guide reamer 07984-0980000, and later C70 bearing-driver handle A 07749-0010000. The manuals also reference clutch, steering-head, float-level, valve, bearing, and rear-shock service tools by application.

The carburetor chapter warns that forcing the pilot screw or limiter cap can damage the screw and its seat. The top-end sections stress keeping the camshaft and rocker-arm oil passages clear; blockage can starve those parts of lubrication after repair.

Gasoline, exhaust, battery electrolyte, and charging-system gases are specifically identified as shop hazards. Keep fuel work away from ignition sources, ventilate running-engine tests, and isolate the battery before electrical or starter-system repair.