1994–1997 Yamaha VX750 / VX800 / MM800 Snowmobile Factory Service Manual Set (P/N LIT-12618-MM-00)

This Yamaha factory service manual set covers the 1994–1997 VX750, VX800, and MM800 snowmobile series under collection reference LIT-12618-MM-00. It combines the VX750U/VX750STU service manual (P/N LIT-12628-01-56) with VX800V/VX800STV and VX800A/MM800A supplements, which supply variant-specific updates for use with the base manual.

• Engine repair: Engine removal, crankcase separation, crankshaft and piston inspection, reed-valve service, reassembly, and recoil-starter repair.

• Fuel and lubrication: Mikuni TM33 carburetor overhaul and synchronization, fuel-pump checks, Yamaha Autolube bleeding, and oil-pump cable adjustment.

• Clutches and drive train: Primary and secondary sheave service, jackshaft and chaincase work, belt positioning, and altitude-specific clutch and gearing charts.

• Chassis and suspension: Steering and ski alignment, Telescopic Strut Suspension (T.S.S.), slide rail suspension overhaul, and track replacement and adjustment.

• Brakes: Cable-operated brake service plus VX800A/MM800A hydraulic caliper and master-cylinder repair, parking-brake adjustment, and hydraulic bleeding.

• Cooling system: Radiator and heat-exchanger removal, water-pump service, cap-pressure and thermostat testing, and cooling-system bleeding.

• Electrical diagnosis: Wiring diagrams and troubleshooting charts for ignition, lighting, warning lights, fuel indication, and grip and thumb warmers.

Yamaha wrote the base manual for dealers and qualified mechanics who already understand snowmobile maintenance and repair.

Engine Overhaul and Carburetor Service

Engine overhaul specifications include cylinder-bore, piston-to-cylinder clearance, and crankshaft-deflection data. The repair chapters cover paired crankshafts and drive gears, intake manifolds, and reed valves.

Crankcase and Crankshaft exploded views support engine assembly, with component-specific torque references for the base manual and supplements, including magneto-rotor tightening.

Carburetor troubleshooting charts address hard starting, poor idling, hesitation, and power loss. The manual warns that unsuitable carburetor settings can damage or seize pistons; its altitude and temperature charts help match jetting to operating conditions.

Clutches, Brakes, and Chassis

Clutch setup: Clutch Setting Data and Gearing Selection charts distinguish the configurations for different elevations. Secondary-sheave procedures identify the sheave compressor, 90890-01712 / YS-28891. The primary-sheave section identifies the left-hand-threaded spider and warns that mishandling can crack the spider or sheaves.

Because working with high-tension components and volatile fluids carries inherent risks, observe the manual's precautions for clutch service and fuel handling.

Brake variants: The base manual covers a cable-operated disc brake. The VX800A/MM800A supplement adds hydraulic-brake overhaul and separate parking-brake procedures, so the brake system determines which service section applies.

Suspension setup: Chassis documentation covers stopper band settings, track tension, spring preload, and ski alignment. Separate VX800 and MM800 suspension views show the different assemblies. Cable Routing drawings identify harness and hose placement around the oil-pump bracket and starter rope, helping avoid interference during reassembly.

Cooling System Testing

Coolant Flow drawings trace the radiator and heat-exchanger circuit. The cooling chapter covers pressure testing, thermostat inspection, and replacement of water-pump bearings and the mechanical seal, along with coolant replacement and air bleeding.

Electrical Fault Isolation

The VX800V/VX800STV and VX750/VX750ST wiring diagrams show connectors, wire colors, and voltage-regulator connections. Dedicated diagnostic charts cover no-spark faults and the Throttle Override System (T.O.R.S.), supported by coil-resistance and voltage tests that help isolate the faulty circuit. Ignition-timing specifications are also included.

A Sample of Ring, Oil-Pump, and Cooling Specifications

These examples represent a small selection of the engine, lubrication, and cooling data in the manuals.

For the covered models, the installed top and second piston-ring end gap is 0.35–0.55 mm. The specified oil-pump cable adjustment distance is 28–30 mm.

The cooling tables specify a 6:4 coolant-to-water ratio and a filler-cap opening pressure of 80–100 kPa. The pressure range refers to the cap-opening specification.

PDF Bookmarks and Included Publications

Search, navigation, and wiring detail: PDF text search is not available. Embedded bookmarks link to the three publications and their service sections. Small labels in the two full wiring diagrams require zooming; those diagrams are sideways in the file.

One printable English PDF contains 305 pages, with the publications divided as follows:

The total also includes one separate collection cover. The publication counts already include their supplied covers, front matter, and diagrams.