2009–2012 Kymco Sento 50 / Kiwi 50 / Kiwi 100 Scooter Service Manual

• Model-code coverage: KYMCO Sento 50 and Kiwi 50 SD10RA, SD10RB, and SD10RC, plus Kiwi 100 SG20TA and SG20TB, in a 164-page, 17-section PDF published by KYMCO's Overseas Service Department within its Quality Technology Division.
• Engine repair: Covers engine removal and installation, engine-hanger inspection, oil-pump service, camshaft and valve work, cylinder and piston inspection, crankcase separation, crankshaft checks, and final reassembly.
• Fuel-system service: Details CVK carburetor removal, auto-bystarter testing, air cut-off and vacuum-chamber work, float and accelerator-pump inspection, float-level measurement, and pilot-screw and idle adjustment.
• CVT and final drive: Provides drive-belt replacement, drive-pulley and weight-roller inspection, clutch/driven-pulley disassembly, kick-starter service, driven-face bearing replacement, and final-reduction gear, bearing, and oil-seal repair.
• Brake, steering, and suspension work: Covers hydraulic front-brake bleeding, master-cylinder and caliper repair, the front-brake free-play callout for SD10RB/SG20TB, front-fork overhaul, steering-head race replacement, rear drum-brake service, and shock-absorber work.
• Electrical diagnosis: Walks through battery and charging tests, regulator/rectifier inspection, A.C. generator removal, CDI/ignition-coil/pulser-coil checks, starter-motor and relay repair, switch continuity tests, and fuel-gauge diagnosis.
• Diagrams and fault isolation: Supplies the Charging System Diagram, Ignition System and Starting System circuits, a lubrication-system schematic, cable-and-harness routing views, and exploded powertrain and front-suspension assemblies, backed by troubleshooting charts for starting, power, carburetion, charging, and no-spark faults.

Exact Engine and Chassis Scope

The 50cc group is built around a 49.5cc engine with a 17 mm CVK carburetor, while the Kiwi 100 uses a 101.7cc engine and 20 mm CVK. Both are air-cooled, single-cylinder OHC four-strokes with CDI ignition, electric and kick starting, a dry multi-disc clutch, and a CVT with automatic centrifugal operation and two-stage final reduction. Coverage is specific to the carbureted configurations identified by the model codes above.

Because the deeper procedures call for dedicated pullers, holders, compressors, precision measuring equipment, and electrical testers, this service manual is suited to professional technicians and experienced owners already comfortable with engine, brake, and electrical repair.

Variant-Specific Specifications and Repair Data

The factory tables distinguish the 50cc and 100cc configurations by carburetor settings, spark-plug application, valve clearance, idle speed, compression, rear-tire specification, reduction ratio, and final-drive oil capacity. Component sections add fastener torque tables, wear limits, runout checks, fit and clearance data, charging and ignition test values, brake disc/drum and hydraulic-component limits, and suspension specifications.

Repair coverage goes beyond routine adjustment. The manual documents oil-pump rotor inspection; camshaft, rocker-arm, valve-spring, and cylinder-head checks; piston-ring, bore, and connecting-rod measurements; crankshaft big-end and runout inspection; and transmission-shaft, gear, bearing, and seal replacement. Most sections open with an assembly view and service information, then move into troubleshooting, removal, disassembly, inspection, assembly, and installation.

Brake Configurations, Circuits, and Workshop Tools

The adjustment section specifically identifies front-brake lever free-play coverage for SD10RB and SG20TB. A dedicated hydraulic front-disc subsection covers fluid replacement and bleeding, pad and disc service, master-cylinder overhaul, and brake-caliper disassembly and assembly. Wheel runout, steering-stem bearings, fork disassembly and oil filling, rear brake shoes, wear-indicator indexing, and rear shock service are handled in the same chassis sequence.

Electrical pages trace the A.C. generator, regulator/rectifier, battery, auto bystarter, CDI unit, ignition coil, pulser coil, starter relay, brake-light switches, and starter motor. Connector checks and handlebar-, ignition-, horn-, stop-, and fuel-unit continuity tables provide component-level fault isolation.

The special-tool chart identifies factory references such as the oil-seal and bearing installer A120E00014, valve adjuster A120E00036, clutch spring compressor A120E00034, universal holder A120E00017, and flywheel puller A120E00001. The carburetor procedures warn that forcing the pilot screw against its seat can damage the seat; compressed-air cleaning can damage the vacuum diaphragm unless it is removed first. During brake repair, fluid must be kept off coated and plastic surfaces, and oil or grease must not contaminate pads, discs, drums, or linings because braking performance can be reduced.