Yamaha XV1600A(L) Wild Star 1999 Service Manual (P/N 5JA1-AE1)

This 468-page PDF is Yamaha's factory service manual for the 1999 XV1600A and XV1600AL Wild Star, identified on the cover by code 5JA1-AE1. The First Edition is dated December 1998 and covers the 1,602 cc air-cooled OHV V-twin, dry-sump lubrication system, constant-mesh five-speed transmission, belt final drive, and Mikuni BSR40 carburetor. Yamaha produced the book primarily for its dealers and qualified mechanics; it assumes a working knowledge of motorcycle maintenance and repair rather than teaching basic shop practice.

• Engine repair procedures: engine removal and installation; rocker arms, push rods, oil-pressure-operated valve lifters, camshafts, automatic decompression, cylinder heads, valves, pistons, crankcase, oil pumps, crankshaft, and connecting rods.
• Drivetrain work: clutch and primary-drive inspection, shift-shaft service, generator and starter-clutch removal, transfer-gear-case repair, transmission disassembly, and drive-belt and sprocket installation.
• Chassis service: wheel and brake-disc inspection, static balancing, brake master-cylinder and caliper overhaul, hydraulic brake bleeding, front-fork rebuild, steering-head service, and rear shock and swingarm removal.
• Fuel and electrical diagnosis: carburetor teardown, fuel-level and throttle-position-sensor adjustment, fuel-pump and fuel-cock tests, air-induction checks, starter-motor repair, charging-system tests, and system-specific fault isolation.
• Drawings and reference data: exploded assembly views with job-order charts, engine- and transfer-oil flow diagrams, cable-routing drawings, electrical component and coupler locations, circuit diagrams, and full EUR/AUS wiring schematics.

Air-Cooled V-Twin and Drivetrain Work

The feature section explains the twin-plug ignition layout, automatic decompression mechanism, and oil-pressure-operated valve lifters. Those lifters normally maintain zero clearance, but the manual still provides inspection and manual correction procedures for maladjusted or worn valve pairs, plus lifter bleeding and installation guidance. The overhaul chapters continue through camshaft and gear alignment, decompression-system inspection, valve and valve-seat work, piston and ring checks, big-end bearing clearance and selection, connecting-rod service, crankcase assembly, and transmission inspection.

Drivetrain coverage is equally specific. The wet multi-disc clutch chapter addresses friction and steel plates, spring plate, clutch boss, housing, pressure plate, pull rod, and primary drive. Separate sections cover the shift shaft and stopper lever, generator rotor and starter clutch, middle driven shaft, transfer-oil pump, transfer gear case, main axle, drive axle, shift drum, and shift forks.

Fuel, Electrical, and Diagnostic Coverage

The single BSR40 carburetor is covered from removal and disassembly through fuel-level measurement, throttle-position-sensor adjustment, fuel-pump and fuel-cock testing, and air-induction-system inspection. The carburetor chapter does not contain a separate multi-carburetor synchronization procedure.

Electrical chapters provide component and coupler location views plus circuit-by-circuit troubleshooting for ignition, electric starting and cutoff logic, charging, lighting, signaling, fuel-pump control, and carburetor heating. The self-diagnosis section isolates faults in the throttle-position sensor, speed sensor, decompression solenoid, and fuel-level meter. The two final full wiring diagrams are specifically labeled XV1600A for EUR and XV1600AL for AUS, an important match point for electrical repair.

Factory Data, Tools, and Repair Cautions

Specification sections supply component-specific torque tables, compression and oil-pressure checks, fuel-pump test data, fluid capacities, lubrication points, wear limits, clearances, battery-charging guidance, and electrical resistance and output values. Yamaha tool numbers and stated uses are provided for items such as flywheel puller 90890-01080, damper-rod holder 90890-01294, belt-tension gauge 90890-03170, clutch-holding tool 90890-04086, and oil-pressure gauge 90890-03153.

For deeper repair, the shift-drum segment must be placed in the illustrated position before the crankcase halves are separated or joined, or its teeth can contact and damage the case. Brake master-cylinder and caliper internals must not be cleaned with solvent because it can distort the piston seals and lead to leakage. Before wheel, fork, brake, or engine work, support the motorcycle securely on a suitable stand or lift and follow the manual's precautions for fuel, brake fluid, the maintenance-free battery, hot engine parts, and the gas-charged rear shock.