1991–1999 Yamaha XTZ660 Service Manual (P/N 3YF-ME1)

• Exact model coverage: A 414-page PDF scan of Yamaha's XTZ660 Tenere ('91) Service Manual, identified on the cover by code 3YF-ME1. It covers model codes 3YF1, 3YF2, and 4BW1 rather than the full 1991-1999 production run.
• Machine identification: Maps 3YF1 to A/B/D/DK/F/GB/GR/I/N/NL/PRT/S/SF, 3YF2 to CNR/E, and 4BW1 to A/CH. Factory tables give frame starts 3YF-000101 and 4BW-000101, engine starts 3YF-000101, 3YF-029101, and 4BW-000101, plus VIN start JYA3YFS0*MA029101 for CNR/E.
• Engine repair depth: Covers engine removal and remounting, disassembly, inspection, repair, assembly, and adjustment. Major groups include the cylinder head and valve train; piston, crankshaft, and balancer; clutch and five-speed transmission; and starter, lubrication, and cooling drives.
• Fuel and cooling service: Details Teikei Y26PV carburetor removal, sectional construction, disassembly, inspection, assembly, fuel-level adjustment, and fuel-pump testing, together with radiator, thermostat, water-pump, pressure-test, and coolant-replacement procedures.
• Chassis procedures: Includes wheel removal and static balancing, brake-pad and hydraulic component repair, caliper and master-cylinder overhaul, brake bleeding, front-fork service, steering-head work, swingarm clearance adjustment, and drive-chain and sprocket inspection.
• Electrical diagnosis: Supplies the full XTZ660 circuit diagram and separate ignition, starting, charging, lighting, signal, and cooling-system circuits, supported by switch-terminal checks, component test data, and system-specific troubleshooting.
• Workshop reference: Pairs exploded assembly views with component torque tables, capacities, wear limits, clearances, and electrical test specifications. System orientation comes from the lubrication chart, coolant diagram, cable-routing layouts, and carburetor sectional view.

Factory Workshop Scope

Yamaha states that this manual was written primarily for Yamaha dealers and qualified mechanics, and it assumes a basic understanding of motorcycle repair concepts and procedures. It is therefore suited to users with that workshop background, not to a first-time mechanic looking for a basic repair primer.

The work is organized in sequential factory procedures. Exploded views appear ahead of the disassembly sections, while boxed data identifies the required special tools, lubricants, tightening points, wear limits, and electrical checks. The periodic service chapter also covers valve-clearance and cam-chain adjustment, ignition-timing and compression checks, oil-pressure inspection, carburetor and fuel-line service, cooling-system maintenance, brake adjustment and bleeding, steering-head adjustment, and suspension inspection.

Fuel handling, hot pressurized coolant, hydraulic brakes, and the nitrogen-charged rear shock all present real service hazards. The manual's safety notices and the technician's own training should govern work on those systems.

3YF1, 3YF2, and 4BW1 Differences

The variant information goes beyond a generic 3YF/4BW label. The carburetor data distinguishes identification marks 3YF 00 and 4BW 00, with an A/CH-specific jet-needle specification. The wiring diagram separately identifies the pass switch used on the Austria/Switzerland configuration. For CNR/E machines, the identification section uses the VIN starting point and the separate 3YF-029101 engine start instead of the standard 3YF frame-number scheme.

The manual supplies starting identifiers, not closed serial-number ranges. Its stated coverage is the 1991 XTZ660 and the listed launch configurations; it does not contain the later-year supplements needed to establish blanket coverage through 1999.

Repair Detail, Tools, and Scope Limits

The overhaul material reaches well inside the engine. It covers valve-seat refinishing and valve-guide replacement, timing-chain and decompression components, crankcase separation, crankshaft and balancer installation, clutch and transmission inspection, oil delivery, starter clutch, and final engine adjustment. Related tables carry the factory fit, wear, lubrication, and tightening data needed to evaluate parts before reassembly.

Country-specific tool numbers are listed side by side. Representative examples include the valve-adjusting tool YM-08035 / 90890-01311, crankcase separator YU-01135-A / 90890-01135, universal clutch holder YM-91042 / 90890-04086, and fork-seal driver YM-33963 / 90890-01367 with adapter YM-08020 / 90890-01374.

The crankcase section warns against forcing the halves apart or striking the gasket surfaces, while the camshaft procedure warns that moving the crankshaft during installation can produce incorrect valve timing and engine damage. The rear-suspension chapter covers shock removal, inspection, handling, and installation, but expressly prohibits opening the pressurized shock assembly; an internal shock rebuild is outside this manual's repair scope.

For fault isolation, the final chapter organizes probable causes for hard starting, poor idle or high-speed performance, shifting faults, clutch slip or drag, overheating, weak brakes, fork leakage, unstable handling, and lighting or signal failures. Each fault list points back to the relevant inspection, adjustment, or repair section.