Yamaha Exciter EX570/EX570E Snowmobile Service Manual Set, 1987–1991

The two main manuals address different carburetor and electrical configurations. The HP/EHP supplement provides separate primary-sheave procedures and specification tables for those variants.

Missing pages: The EX570L section omits printed pages 2-22 and 3-13; the EX570M/EX570EM section omits printed page 3-13. These gaps interrupt the starter-cable adjustment and piston-pin/crankshaft inspection material.

PDF Search, Bookmarks and Wiring Detail

Finding procedures and reading diagrams: OCR text search is available, although recognition errors affect some words and identifiers. Embedded bookmarks organize both main manuals and link to the HP/EHP specifications; the supplement’s other sections have no dedicated bookmarks. Small wiring labels are readable with zoom in the checked diagrams.

One printable, English-language PDF contains 578 pages. The total includes six memo pages and the supplement’s four introductory pages, along with the contents, symbol guides and diagrams within the listed sections.

Engine Overhaul, Clutch Service and Electrical Diagnosis

The following selected contents outline the main workshop coverage. Storage preparation and headlight-beam adjustment are additional examples of topics included.

• Engine repair: Step-by-step procedures for engine removal, crankcase separation, piston and cylinder inspection, CDI magneto service, reassembly and recoil-starter repair.

• Fuel and lubrication: Mikuni carburetor disassembly, jet and float inspection, synchronization, fuel-pump checks, oil-pump adjustment and delivery-line bleeding.

• Cooling system: Water-pump removal and seal replacement, cooling-line service, coolant bleeding and thermostatic-valve testing.

• Clutch and final drive: Primary and secondary sheave disassembly, wear inspection, assembly, belt alignment, drive-chain housing service and sprocket inspection.

• Brakes and chassis: Brake-pad inspection and adjustment, slide-rail suspension overhaul, track removal, steering inspection and front-suspension service.

• Electrical troubleshooting: Ignition and throttle-override tests, lighting and indicator-circuit diagnosis, plus EX570EM electric-start and charging-system procedures.

• Tuning references: Altitude and temperature jetting charts, clutch engagement and shift-setting data, gear-ratio charts and suspension-setting guidance.

Yamaha wrote this service material primarily for its dealers and qualified mechanics, assuming an existing understanding of mechanical repair.

Carburetor Setup and Two-Stroke Lubrication

Variant differences: The EX570L material covers the Mikuni B44-36 carburetor, while the EX570M/EM sections cover the VM-38 arrangement. Their jetting tables and adjustment details give mechanics the configuration-specific references needed when planning carburetor work.

The Main Jet Selection Chart relates running symptoms and spark-plug condition to carburetor checks. High-altitude tables coordinate jetting with clutch and gearing choices. The tuning sections warn that operating without the intake silencer can create a lean mixture and severely damage the engine.

Oil delivery: Bleeding procedures address disconnected oil-system components, an emptied oil tank and a machine that has been turned on its side. Pump inspection and adjustment are covered separately from routine oil-level checks.

Internal Engine Work and Cooling Components

The engine chapters provide piston-to-cylinder measurements, ring-clearance checks, crankshaft inspection data and illustrated assembly references. Reassembly coverage includes bearing and seal positioning, piston orientation and the distinct tightening requirements for cylinder-head bolts and nuts.

The Coolant Flow diagram supports the cooling-line sections, which cover heat exchangers and hoses. Water-pump instructions address the impeller, shaft, seals and drive belt; thermostat testing provides a separate check for temperature-control faults.

Sheave Service and Chassis Adjustments

The EX570L and EX570M/EM primary-sheave sections identify the left-hand-threaded spider, Loctite 548 requirements and curing precautions. They also warn that poor support or mishandling during high-torque work can crack the sheaves or spider.

The HP/EHP supplement documents a different primary-sheave assembly. Its component inspections and assembly details should be matched to that configuration.

Suspension coverage extends to pivot arms, torsion springs, wheels, bearings and slide runners. Steering and ski sections include alignment and component inspection. Spring-loaded sheaves and nitrogen-charged shock absorbers require the precautions and tooling described in the manual.

Tracing Ignition and Electric-Start Faults

The ignition charts test the throttle-override switches, ignition coil, source coil and pickup coil before reaching the CDI-unit diagnosis. Separate EX570L, EX570M and EX570EM wiring diagrams distinguish the relevant circuits and wire-color codes.

For the EX570EM, the electrical chapters go beyond a wiring overview: they cover starter-relay diagnosis, starter-motor disassembly, brush and commutator inspection, and battery-charging tests.

Selected Lubrication, Cooling and Charging Checks

The EX570L oil-pump adjustment section specifies a minimum stroke of 0.15–0.20 mm. Its thermostat inspection section gives an opening-temperature range of 50–55°C.

For the EX570EM, charging-system diagnosis includes a battery charging-voltage check of 14–15 V at 5,000 r/min, alongside component tests used to investigate a charging fault.