Honda CT125 CT125A Trail 125 2020-2022 Service Manual

Honda's own confirmed press materials trace the direct lineage this exact bike revives: "milestone models included the 1964 CT200 Trail 90, the 1969 CT70 Trail 70 and the 1981 CT110. Over the course of nearly three decades, well over 725,000 units from the CT series were sold in the U.S. before it disappeared for several decades. Then in 2019, a concept CT125 debuted at the 46th Tokyo Motor Show, paying tribute to the popular platform of old. It received rave reviews, along with requests for a production model, and that wish was granted with the introduction of the 2021 Honda Trail 125." Autotrader's own buying guide confirms the genuine global naming this platform carries: "known as the CT125 Hunter Cub in Asia, the American version shares the same ruggedness and simplicity as its Asian cousin."

Power comes from a 124.9cc air-cooled SOHC single-cylinder four-stroke engine, 2 valves, with a 52.4mm bore and 57.9mm stroke and a 9.3:1 compression ratio, delivering drive through PGM-FI fuel injection and a genuine 4-speed manual transmission with semi-automatic clutch — the same fundamental engine architecture Honda used in the Super Cub C125 of the same era. Autotrader's own confirmed model-year comparison confirms this exact 2020-2022 range represents a genuinely stable, unchanged configuration: "what's new for 2022? Nothing, except a slight price hike. The colors, specs, and features are completely the same between both the 2021 and 2022 model years. We think Honda's leadership knew that they shouldn't change a proven winner and we're glad they didn't."

ADV Pulse's own detailed account confirms exactly what would eventually change, and by extension confirms this precise engine and gearbox specification is genuinely unique to the 2020-2022 range this manual covers: "for 2023, the Trail125 gets the 124cc air-cooled, two-valve, overhead-camshaft, four-stroke, single-cylinder engine that the Super Cub received in 2022. Fuel-efficient and durable, the powerplant combines the bottom end (with redesigned crankcases) from the Japanese-market C110 with the SOHC, two-valve top end of the Grom... compared to its predecessor, the 2023 Trail125 is more undersquare, with a 50.0mm bore and a 63.1mm stroke (previously 52.4mm x 57.9mm), and compression ratio is 10.0:1 (previously 9.3:1)" — genuine confirmation that a bike from this 2020-2022 range runs meaningfully different internal engine geometry than the model years that followed it.

Honda's own confirmed styling account for this exact generation details the deliberate design continuity built into the modern reinterpretation: "the many improvements to the function and capability of the original CT series have not detracted from the distinctive CT design, which is carefully preserved in the modern Trail 125. With the goal of balancing the image of a tough-yet-modern machine, Honda's designers simplified the surfaces of each part on the frame while preserving the symbolic elements such as the upswept muffler, air-cleaner cover, fuel tank, rear carrier, steel front fender, turn signals, footpegs." Autotrader's own confirmed braking specification lists a "front, single 220mm hydraulic disc; ABS" configuration standard across this range.

ADV Pulse's own account confirms a genuine, real safety recall specific to this exact generation worth knowing before servicing an early example: "American Honda has launched a safety recall on certain 2021 Trail 125 (CT125A)" models — worth cross-referencing against the specific VIN before assuming any given 2021 unit is unaffected. That same source confirms a genuinely candid owner account of one real mechanical criticism worth knowing about this platform's semi-automatic clutch operation: "I bought a new one last year and sold it with twelve miles on it. The issue was the clutchless shifting. Shifting from gear to gear, up or down, was abrupt every time... very charming bike," though this same reviewer's frustration was balanced against widespread genuine enthusiasm and long waiting lists at dealerships, per that same source's separate comment thread confirming units were "practically sold out" with "waiting lists double digit deep." The CT125A model code within this range denotes the ABS-equipped configuration, standard across the platform for the US market throughout this exact 2020-2022 span.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a 2020-2022 Trail 125 CT125/CT125A running the way it was built to.