1991 Yamaha XT225D & XT225DC Service & Repair Manual (P/N LIT-11616-XT-25)

This Yamaha service manual (P/N LIT-11616-XT-25, 1st Edition, June 1991) covers the 1991 XT225D and XT225DC in the 4BE model series, including US non-California, California, and Canadian configurations.

• Engine overhaul: Engine removal, cylinder-head and valve service, piston-ring inspection, crankcase separation, crankshaft installation, and camshaft timing.

• Clutch and transmission: Wet multi-disc clutch repair, balancer assembly, shift-fork and shift-drum inspection, and electric starter-drive service.

• Carburetion: Mikuni BST34 disassembly, diaphragm and coasting-enricher inspection, float-height adjustment, and fuel-level checking.

• Brakes and wheels: Front caliper and master-cylinder repair, hydraulic bleeding, rear drum-brake service, wheel-bearing replacement, and spoke inspection.

• Suspension and steering: Front fork rebuilding, oil-seal replacement, steering-bearing service, swingarm clearance adjustment, and rear shock settings.

• Electrical diagnosis: CDI ignition tests, starting-interlock checks, charging-system troubleshooting, starter-motor repair, and lighting and signal circuit diagrams.

• Maintenance references: Separate US and Canadian schedules, lubrication charts, cable-routing illustrations, and California emission-hose routing.

Written primarily for Yamaha dealers and qualified mechanics, this manual assumes a basic understanding of motorcycle repair and use of the specified tools and test equipment.

Engine Overhaul and Drivetrain Repair

The overhaul chapter covers SOHC valve-gear inspection, valve-seat refacing, valve-guide replacement, cylinder and piston measurement, and crankshaft inspection. Exploded views identify the clutch plates, balancer gears, transmission shafts, and shifter components, with related wear limits and assembly checks.

Fastener tables include separate specifications for the AC generator rotor and cam sprocket. The tool list identifies crankcase separator YU-01135-A and rotor puller YM-01080-A for the associated service work.

Oil-service procedures distinguish routine changes, filter replacement, and total fill. They also cover the strainer, filter-cover fasteners, and the oil-flow check at the cylinder head.

The camshaft-installation section identifies crankshaft movement during assembly as a cause of component damage or incorrect valve timing.

BST34 Carburetor and California Emissions

The carburetor sectional view explains the vacuum-operated piston valve and coasting enricher. Inspection instructions address diaphragm tears, jets, the starter plunger, and the needle-valve/seat pair, while separate procedures cover float height and measured fuel level.

The specification tables distinguish US and Canadian carburetor settings. XT225DC California coverage adds canister inspection and hose routing through the roll-over valve.

Brake, Fork and Swingarm Service

Front brake coverage includes caliper piston seals, the master-cylinder kit, disc inspection, and bleeding. Rear drum-brake procedures cover shoes, springs, the brake camshaft, and wear-indicator alignment.

Steering-head bearing service and swingarm shim calculations address bearing fit and side clearance on the diamond-frame chassis. Front fork instructions include damper-rod removal, bushing inspection, and seal installation.

Fork disassembly notes identify bottoming the inner tube as a potential cause of oil-lock-piece damage. Rear shock coverage includes removal, inspection, preload and damping adjustment, and disposal precautions; the pressurized nitrogen cylinder is not intended for internal disassembly.

Ignition, Starting and Charging Diagnostics

The XT225D/DC circuit diagram is supported by separate ignition, electrical starting, charging, lighting, and signal diagrams. Starting-circuit explanations distinguish neutral operation from the clutch-and-sidestand interlock conditions.

The no-spark charts combine switch, relay, coil, and wiring checks, helping distinguish an interlock fault from an ignition-component fault before selecting replacement parts. Starter-motor coverage includes armature, commutator, brush, and insulation checks.

A separate color wiring sheet is labeled XT225N/XT225NC. It is an additional reference diagram, not a second service manual or full repair coverage for those models.

Electrical testing and brake work require the precautions specified with the relevant procedures.

Examples of Cold Valve Clearances and Ignition Test Data

These figures are a small sample of the adjustment and electrical-test data in the manual.

For XT225D/XT225DC, cold valve clearance is 0.05–0.09 mm at the intake and 0.15–0.19 mm at the exhaust.

At 20°C (68°F), the pickup/pulser coil specification is 656–984 ohms between the red and white leads. The CDI charge-coil specification between the brown and green leads is 584–876 ohms at the same temperature.

Searchable Text, Bookmarks and Wiring Detail

Search and diagram access: OCR text is searchable across the main manual, and embedded bookmarks link to chapters and subsections. Front-cover text is not searchable, and OCR can misread some identifiers. Small wire-color and connector labels are readable when enlarged.

One printable English PDF contains 371 pages total: 13 front-cover and introductory pages, 356 service-manual pages, one additional wiring-diagram page, and one rear cover. All are included in the total.