1998–1999 Yamaha XV16AL, XV16ALC, XV16ATL, AV16ATLC Factory Service Manual (P/N LIT-11616-12–56)

• Covers Yamaha XV16AL/XV16ALC and XV16ATL/XV16ATLC Road Star models; the manual identifies fitment by these model codes rather than printing a separate model-year range.
• Yamaha-produced factory service manual P/N LIT-11616-12-56, also marked 4WM-28197-E0, First Edition, October 1998; the supplied PDF is 449 pages.
• Documents the 1,602 cc air-cooled OHV V-twin, hydraulic valve lifters, auto-decompression system, BSR40 Mikuni carburetor, 5-speed transmission, and secondary belt drive.
• XV16AT-specific pages cover the windshield, backrest, saddlebags, passenger footrests, and related stays; California-specific data distinguishes carburetor ID 4WM2 10 from 4WM1 00 and documents the evaporative-emission layout.
• Removal and disassembly sections use exploded diagrams with job instruction charts, while torque data is split between general, engine, chassis, and component-specific specifications.

System Architecture and Data Preview

The engine section goes well beyond basic tune-up data. It covers rocker arms, push rods and valve lifters, camshafts and the decompression system, cylinder heads, valves and guides, cylinders and pistons, clutch, generator and starter clutch, transfer gear case, crankcase, engine oil pump, crankshaft and connecting rods, and the transmission with its shift drum and forks. The hydraulic lifter system normally maintains zero valve clearance; the manual still provides a factory check/adjustment procedure for maladjusted or worn valve-train components and a separate valve-lifter bleeding procedure.

The powertrain is a constant-mesh 5-speed with a wet multi-disc clutch and belt secondary reduction. Fuel delivery centers on one BSR40 Mikuni carburetor and an electric 4WM Mitsubishi fuel pump. The twin-spark layout uses two spark plugs per cylinder. Electrical coverage is equally specific: transistorized coil ignition, starting-circuit cutoff logic, charging, lighting, signaling, fuel-pump control, carburetor heating, and self-diagnosis. The diagnostic system monitors the throttle-position sensor, speed sensor, decompression solenoid, and fuel-level meter, with indicator-code patterns of 3, 4, 6, and 8 respectively. A speed-sensor fault invokes an approximately 4,400 r/min limiter, while a decompression-solenoid fault can inhibit starter operation.

Factory Repair and Diagnostic Procedures

Factory repair procedures cover engine removal and installation; camshaft, cylinder-head, valve, piston, clutch, crankcase, oil-pump, crankshaft, connecting-rod, and transmission work; carburetor disassembly and fuel-level/TPS adjustment; front and rear wheel service and static balancing; brake master-cylinder and caliper overhaul; hydraulic brake bleeding; front-fork overhaul; steering-head service; swingarm and rear-shock work; and drive-belt/drive-pulley removal and installation.

For electrical repair, the manual provides circuit-based tests for ignition, electric starting, charging, lighting, signaling, the fuel-pump system, carburetor heating, and the four self-diagnostic circuits. The troubleshooting chapter ties symptoms such as starting problems, incorrect idle, poor high-speed performance, difficult shifting, jumping out of gear, clutch slip or drag, overheating, poor braking, fork faults, unstable handling, and lighting faults back to the relevant mechanical, fuel, or electrical checks.

Specification Highlights

Key engine figures include 95 × 113 mm bore and stroke, 8.3:1 compression ratio, 850–950 r/min idle speed, and standard compression pressure of 1,200 kPa (171 psi) at 200 r/min. The dry-sump oil system holds 5.0 L total, with 3.7 L specified for a periodic oil change without filter replacement and 4.1 L with the filter replaced. Transfer-gear oil capacity is 0.4 L, and fuel-pump output is 15–20 kPa.

The UBD-0568 drive belt is specified at 7.5–13 mm slack on the sidestand or 14–21 mm on a suitable stand, measured with 4.5 kg (10 lb) force. Front-fork service data calls for Yamaha 5WT oil, 554 cm³ per leg, with a 110 mm oil level under the stated measuring condition. The braking system uses DOT 4 fluid with dual front discs and a single rear disc. Representative assembly torque data includes 160 Nm for the generator rotor bolt, 150 Nm for the rear wheel axle nut, and 23 Nm for brake-disc bolts.

The maintenance chart schedules a valve-clearance check every 15,000 mi (24,000 km), drive-belt tension checks every 2,500 mi (4,000 km), and transfer-gear oil replacement every 16,000 mi (25,000 km) or 24 months. Variant data is not treated as interchangeable: wet weight is 332 kg (732 lb) for XV16A and 347 kg (765 lb) for XV16AT, while the rear-shock installed spring length is 172 mm versus 169 mm. The carburetor specification also distinguishes a 1.0 pilot outlet for XV16A from 1.1 for XV16AT.

Diagrams, Wiring, and Special Tools

Named visual references include the Engine Oil Lubrication Chart, Engine Oil Flow Diagrams, Transfer Gear Oil Flow Diagrams, Cable Routing, Starting Circuit Cutoff System Operation, and the XV16AL/XV16ALC/XV16ATL/XV16ATLC Wiring Diagram (For USA and CDN). Factory tool references include fuel level gauge YM-01312-A, belt tension gauge YM-03170, compression gauge YU-33223 with adapter YU-33223-3, dynamic spark tester YM-34487, pocket tester YU-03112, and oil pressure gauge 90890-03153.

A few manual-specific repair traps are worth knowing before work begins. When installing wheel bearings, force must be applied to the outer race rather than the inner race or balls, which can damage the bearing. Solvents can swell and distort brake-caliper piston seals, while incorrect drive-belt slack can either overload the engine or allow the belt to skip and damage the swingarm.

Working on a motorcycle of this size involves heavy assemblies, hydraulic brakes, and supported wheel or engine work. Use the complete Yamaha procedures and appropriate mechanical expertise for hands-on repair; the figures above are a content preview, not a substitute for the full procedure.