Honda CB100 CB125 CL100 SL100 CD125 SL125 Service Manual

This shared-platform family covers one of Honda's most prolific small-displacement runs of the early 1970s — a lineup built around two closely related OHC single-cylinder engine sizes, dressed in three genuinely different bodystyles depending on which model badge a bike carried. The CB100 and CB125 handled street-standard duty; the CL100 and SL100 (and their SL125 sibling) covered scrambler and street-scrambler styling with high pipes and knobby-adjacent tires; and the CD125 filled the economy-commuter role — all sharing enough underlying mechanical DNA that a single factory workshop manual covers the whole family.

The 100cc-class machines (CB100, CL100, SL100) ran a 99cc air-cooled OHC single, delivering a claimed 11.26 hp at 10,500 rpm and a genuine 60 mph top speed on the CB100 — respectable performance for a bike aimed squarely at new riders and budget-conscious commuters. The 125cc-class machines (CB125, CD125, SL125) stepped up displacement for more low-end pull and a taller cruising speed, while retaining the same fundamentally simple, easy-to-maintain single-cylinder architecture that made this entire family popular with first-time owners and shops alike. Both displacement classes ran through a 24mm carburetor and kick-start-only ignition typical of the era, with points-and-condenser electrical systems that owners of surviving examples still service today using the same basic diagnostic approach: verify spark at the plug, check the points, then work backward through the coil and condenser if the fault persists.

Genuine model-year distinctions run through this family in a way any technician working on one needs to know: the CB100 ran largely unchanged from 1970-1973, the CL100 (including the higher-output CL100S variant) covered the same span, the CB125S took over in 1973 running through 1975, and the SL125A covered 1971-1973 — with carburetor specifications changing more significantly on later CB125S production (Clymer's own combined manual notes this update applies "good up until 1978" before further carb changes came in 1980-1982, suggesting some model-year variants extended past this manual's core coverage). Because these bikes share cam chains, carburetors, ignition switches, and other core components across the family, parts interchange is genuinely common — but exact specifications like float height and jetting still vary by model and year, making it worth cross-referencing the specific bike against the manual's model-specific sections rather than assuming identical settings across the whole range.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a CB100/CB125/CL100/SL100/CD125/SL125 running the way it was built to.