2002– Gilera Nexus 500 Scooter Workshop Manual (P/N 633309)

This Piaggio-Gilera workshop manual covers the 2002– Gilera Nexus 500, identified by chassis prefix ZAPM35100 and engine prefix M351M. The cover carries reference 633309.

• Engine repair: Engine removal, cylinder-head and valve service, timing-system assembly, crankcase splitting, crankshaft inspection, and trochoidal oil-pump overhaul.

• CVT and final drive: Drive-belt inspection, variator and driven-pulley service, clutch overhaul, reduction-gear disassembly, and hub-bearing replacement.

• EMS injection: TPS resets, CO% calibration, fuel-pressure and injector-delivery tests, throttle-body checks, and stepper-motor diagnosis.

• Electrical and immobilizer: Wiring diagrams, ECU connector pinouts, charging-system tests, immobilizer decoder checks, key programming, and remote seat-opening programming.

• Cooling system: Water-pump ceramic-seal service, thermostat testing, electric-fan diagnosis, leak checks, coolant replacement, and circuit bleeding.

• Brakes and chassis: Integral brake-system bleeding, caliper overhaul, front-fork repair, steering-headstock servicing, Power Drive strut adjustment, and body-panel removal.

Written for Piaggio-Gilera dealer service mechanics, this manual assumes knowledge of mechanical repair and access to the specified workshop tools and diagnostic equipment.

Engine, CVT, and Lubrication Work

The engine section goes beyond top-end repair into crankshaft and countershaft removal, bearing inspection, and crankcase matching. Cylinder/piston categories, base-gasket selection, wear limits, and component-specific torque tables support reassembly. The connecting rod is not separately replaceable; the manual treats it as part of the crankshaft assembly.

CVT coverage includes clutch friction-material checks, pulley bearings, variator rollers, and belt wear. Tool references include driven-pulley clutch tool 020444Y and driving-pulley lock wrench 020474Y. A driven-pulley exploded view identifies the clutch and pulley assembly.

The lubrication principle diagram accompanies oil-pressure troubleshooting and pump inspection. Magneto flywheel and starter-drive service are also covered; the flywheel removal notes warn that an uncontrolled rotor release can break its magnets.

EMS Diagnosis, Calibration, and Keys

Symptom-based troubleshooting covers no-start conditions, unstable idle, deceleration backfiring, and poor full-throttle performance. The throttle-body fouling comparison helps distinguish contamination from an electronic fault before replacing the assembly.

The diagnostic procedures specify scooter tester 020460Y, ECU interface wiring 020481Y, and fuel-pressure test kit 020480Y. The throttle-position sensor is integral to the precalibrated throttle body; sensor replacement requires replacement of the assembly. The post-catalyst emissions-limit table contains unfilled placeholders.

The EMS circuit diagram and battery charging/starting schematic supplement connector layouts, terminal assignments, and electrical test values. Immobilizer coverage explains master/service-key matching, decoder fault indications, and programming after component replacement.

Water Pump and Cooling Circuit

The cooling circuit diagram supports thermostat, fan-control, and leakage diagnosis. A ceramic-seal service note identifies two interchangeable matched sets: seal ring 485084 with ceramic seal 486216, or 841329 with 841330.

The pump instructions address shaft condition and seal installation, including the warning that oil or grease on the ceramic sealing surface can compromise its seal.

Integral Brakes, Power Drive, and Bodywork

The braking section explains pressure distribution between the linked circuits and provides a brake-pressure relationship chart. It covers pressure-distribution valve replacement, caliper overhaul, and master-cylinder removal and installation. The front-disc runout entry is left as a placeholder.

Power Drive rear-suspension information covers the adjustable strut and Direct Link engine mounting. Chassis change notes distinguish the revised rear brake-hose attachment, longer center stand with its matching stop buffer, and reinforced, heat-shielded helmet compartment. Bodywork procedures identify access to the fuel tank, radiator, instrument panel, and fairings.

Maintenance charts and pre-delivery checks cover routine inspections and final functional checks. When servicing brake hydraulics or suspension geometry, follow the factory safety warnings and wear appropriate protective gear.

A Sample of Fit, Torque, and Tune-Up Data

The following figures are a small sample of the manual's assembly and routine-service specifications.

The A–D cylinder/piston matching table gives a fitting clearance of 0.029–0.043 mm. Its torque tables list 160–175 Nm for the drive pulley nut and 104–126 Nm for the rear wheel axle.

Routine-service data include a 0.7–0.8 mm electrode gap for the listed NGK CR7EKB and Champion RG6YC spark plugs, plus 0.15 mm intake and exhaust valve clearance with the engine cold.

PDF Navigation, Diagram Detail, and Page Count

Search and navigation: Body text and tables are searchable; labels within diagram images are not. Embedded bookmarks cover many sections and procedures, but some lack destinations or open a page early. Small labels in the overall wiring diagram remain partly unreadable when enlarged.

Supplied as one printable, 406-page English PDF. The total includes six introductory pages, including the cover and one blank page, plus three section-ending pages with headers and footers only.