2008 Vespa GTS Super 300 Factory Service Manual

• 396-page, three-file PDF set for the 2008 Vespa GTS Super 300 ie - a 311-page Piaggio dealer-workshop Service Station Manual, an 82-page Owner's Manual marked Ed. 2, and a 3-page A3 wiring-diagram file.
• Engine and automatic-transmission repair procedures cover engine removal, pulley and clutch service, drive-belt inspection, final-drive and hub work, flywheel and starter service, cylinder-head and timing repair, crankcase separation, and lubrication-system testing.
• MIU electronic-injection and immobilizer diagnosis includes no-start and poor-running fault charts, fuel-pump and injector testing, throttle-body service, TPS reset, sensor checks, key coding, and diagnostic-light codes.
• Chassis, brake, and cooling work addresses steering-column and front-hub overhaul, front and rear suspension, swing-arm service, brake-caliper and master-cylinder overhaul, brake bleeding, cooling-system bleeding, thermostat checks, and body-panel access.
• Electrical reference material provides component locations, ground points, harness routing, connector views, ignition and charging diagrams, an EMS circuit diagram, and the full-system wiring schematic with M.I.U. pin-function and connector A/B/C references.
• Reference tables and factory tooling cover tightening-torque tables, fluid capacities, wear limits, assembly clearances, electrical test specifications, pre-delivery checks, labor-time codes, and Piaggio special-tool numbers.

Exact Model Coverage

The workshop volume is specifically titled Vespa GTS Super 300 ie (2008). Piaggio prints the identification as chassis prefix ZAPM45100000 ÷ 1001 and engine prefix M451M ÷ 1001. The engine section is built around the liquid-cooled, four-valve 278.3 cm³ M451M unit and its automatic expandable-pulley transmission. This is model-specific documentation, not blanket coverage for every GTS 300 configuration.

The Owner's Manual adds operating controls, immobilizer use and key programming, routine fluid and tire checks, basic maintenance, technical data, and the scheduled-maintenance chart. The separate wiring file presents the same overall schematic on three bilingual A3 sheets: Italian/English, French/German, and Spanish/Portuguese.

Engine, Transmission, and Fuel-System Repair

Engine coverage goes well beyond routine service. The repair chapters document exhaust and engine removal, CVT cover and pulley work, clutch inspection, drive-belt service, final-drive and hub-bearing repair, stator and flywheel removal, starter service, cylinder-head and timing work, valve and camshaft inspection, cylinder and piston service, crankcase separation, crankshaft checks, oil-pump inspection, and oil-pressure testing.

Factory measurement tables support cylinder/piston class matching, crankshaft and main-bearing selection, valve-train inspection, assembly clearances, wear limits, and piston-position checks used for cylinder-base gasket selection. The lubrication section supplies a circuit diagram along with pressure-test and bypass-valve data.

The MIU injection chapter combines electrical and hydraulic diagnosis. It contains terminal assignments, the EMS circuit diagram, no-start and poor-running troubleshooting charts, fuel-pump circuit checks, pressure and leak testing, filter inspection, injector electrical and hydraulic tests, throttle-body removal and refitting, TPS reset, coolant-temperature and lambda-sensor checks, and radiator-fan control diagnosis. Immobilizer coverage explains virgin-control-unit behavior, master and service-key coding, and one-, two-, and three-flash fault codes.

Electrical, Chassis, and Workshop Reference

Electrical pages map front and rear harness installation, connector locations, chassis and starter-motor ground points, fuses, relays, charging-system checks, stator testing, starter, horn, turn-signal, lighting, fuel-level, dashboard, and sealed-battery circuits. Diagram examples include ignition, battery recharge and starting, level indicators and enable signals, cooling-system circuit, lubrication circuit, and the full M.I.U.-based wiring schematic.

Suspension and brake chapters cover front-wheel-hub overhaul, steering-column removal and rebuild, front shock and caliper-bracket service, swing-arm overhaul, rear shocks, front and rear calipers, brake discs and pads, system filling and bleeding, and front master-cylinder overhaul. Cooling-system work includes circuit layout, bleeding, and thermostat removal, checking, and refitting. Chassis sections show the access and removal work for the instrument panel, handlebar covers, headlight, footrest, side panels, helmet compartment, fuel tank, radiator fan, and related trim.

Listed factory tools include 020460Y scooter diagnosis and tester, 020481Y control-unit interface wiring, 020480Y fuel-pressure check set, 020193Y oil-pressure gauge, 020329Y vacuum pump, and 005095Y engine support. A separate Time chapter supplies factory operation codes and labor-time tables for the covered repair work.

Manual-specific cautions flag two expensive mistakes: incorrect MIU connector handling can damage the control unit, while careless crankcase separation can score the main bushings with the threaded shaft ends. The injection section also makes clear that TPS reset is a factory matching procedure, not an invitation to alter the pre-calibrated throttle stop.

Scope note: this package contains the service manual, owner's manual, and wiring schematic; it does not include a parts catalog. Fuel-system, battery, brake-fluid, and running-engine tests should be carried out with the manual's workshop safety precautions active and with adequate ventilation.