1960s-1970s Honda CB250/CL250/CB350/CL350 Shop Manual Set with SL350 Supplement

This Honda shop manual set covers the 1968 and later CB250, CL250, CB350, and CL350, together with an SL350 Shop Manual Supplement. The main publication comes from Honda Motor Co., Ltd., Service Division. The supplement documents SL350-specific differences and refers to the base manual for shared service and repair procedures.

• Engine repair: Engine removal and installation, cam case and cylinder-head disassembly, valve-seat refacing, piston inspection, and cam-chain tensioner service.

• Clutch and transmission: Clutch inspection and reassembly, crankcase separation, crankshaft checks, gear-shift mechanism service, and kick-starter repair.

• Fuel system and tune-up: Keihin carburetor cleaning, float and jet specifications, throttle synchronization, compression testing, valve-clearance adjustment, and ignition timing.

• Frame and brakes: Front-fork disassembly, steering-stem service, wheel-bearing inspection, brake-shoe wear limits, and rear-suspension checks.

• Electrical diagnosis: Ignition-coil and condenser tests, charging-system checks, starter service, troubleshooting charts, and wiring diagrams for different markets.

• SL350 differences: Engine installation, carburetor settings, front suspension, steering oil damper, rear suspension, wheel equipment, and starter/lighting/kill-switch service.

Written for shop personnel, this manual suits mechanics familiar with engine disassembly, precision measuring tools, and electrical test equipment.

Engine and Transmission Architecture

The engine sections explain construction, removal, and installation, then examine the cam case, cylinder head, and valve mechanism. Engine sectional views and the oil lubrication diagram show how the assemblies fit together and how oil reaches the crankshaft, transmission, camshaft, and hydraulic cam-chain tensioner.

Valve work includes guide inspection, seat refacing, and spring checks. Cylinder and piston tables distinguish standard dimensions from service limits. The special-tool section identifies the CB/CL250 tool set 07000-28601 and CB/CL350 set 07000-28701, with individual tools for valve, piston, and crankcase work.

Lubrication and timing: Separate procedures cover centrifugal oil-filter cleaning and cam-chain tensioner and guide-roller removal and installation. The maintenance section warns that a clogged oil filter can damage moving engine parts.

Splitting the upper and lower crankcases exposes the crankshaft and transmission assemblies. Inspection tables cover connecting-rod clearances, gear backlash, and shift-fork wear; reassembly notes distinguish bearing positions, thrust washers, and retaining clips.

Keihin Carburetors and Running-Fault Diagnosis

Carburetor sectional views explain the slow, primary, and secondary fuel circuits, vacuum piston, float system, and choke. The service material covers cleaning, idle adjustment, and matching the operation of the two throttle valves. Fuel-tank, fuel-cock, strainer, and cap-vent checks address restricted fuel delivery.

Troubleshooting charts separate fuel, ignition, and compression causes of hard starting, poor idle, and power loss. This helps a mechanic identify which system needs testing before committing to engine disassembly.

The air-cleaner section also explains how leaks in the interconnected intake assembly admit unfiltered air and accelerate cylinder-wall and piston-ring wear.

Front Forks, Steering, Wheels, and Brakes

Frame sections detail the handlebar, steering stem, hydraulic front-fork dampers, and rear fork. Separate CB and CL front-cushion cross-sections accompany disassembly, inspection, and seal-installation procedures.

Wheel service includes axle runout, hub-bearing clearances, brake-shoe inspection, and brake adjustment. Rear-cushion work covers removal, spring service, and external damper checks. The pressurized rear damper itself is not to be dismantled; the SL350 supplement specifies replacement of a defective damper unit.

Follow the manual’s precautions for engine handling, brake work, and battery servicing.

Ignition, Charging, and Starting Circuits

Electrical coverage includes the contact breaker, spark advancer, A.C. generator, selenium rectifier, battery, starting motor, and starting clutch. The service-tester section describes continuity, resistance, condenser, ignition-coil, and charging-current checks using the Jonan ST-4B4 tester.

Charging-characteristic charts distinguish operation with and without the SCR regulator. Starter information covers brush servicing, the solenoid switch, and reduction gearing; commutator reconditioning is identified as specialist work requiring suitable tooling.

Wire-harness connection tables accompany General, U.S.A., U.K., and Germany-type wiring diagrams. The SL350 supplement adds its own diagram with the kill-switch circuit and optional equipment identified.

What the SL350 Supplement Adds

The supplement provides its own carburetor settings and engine removal and installation procedures. Chassis differences include the front-fork assembly, steering oil damper, rear-suspension components, and rims with bead spacers for off-road use.

It also describes the spark-arrester muffler assembly and revised electrical equipment. The muffler and exhaust pipe form an integral assembly; the supplement does not provide internal muffler disassembly.

A Preview of Engine Fastener and Lubrication Data

These examples are a small selection of the engine assembly and lubrication specifications included in the publications.

For the CB/CL engine, the cylinder-head cap nuts are specified at 180 kg-cm. The four crankshaft center bearing cap bolts have a specified tightening range of 160–210 kg-cm.

The wet-sump oil-capacity tables list 2 liters for the CB/CL models and 2.2 liters for the SL350. These figures appear in the respective technical-data sections.

PDF Bookmarks, Diagram Detail, and Included Publications

Navigation and readability: Embedded bookmarks lead to the main chapters and SL350 supplement. PDF text search is not available. Small wiring labels require zooming, and some lettering in the Germany-type diagram remains faint. Dark marks also obscure portions of text on some maintenance pages.

The download contains one printable, English-language PDF with 219 pages total, combining these publications:

These counts already include the covers, front matter, publication information, four blank pages, and three memo pages.