Yamaha Enticer 340 & Excel III Snowmobile 1983–1988 Service & Repair Manual (P/N LIT-12618-00-45)

This service manual covers Yamaha Enticer 340 and Excel III snowmobiles, specifically EC340G (8T7) and ET340TG (8T9) variants with the fan-cooled, two-stroke twin-cylinder engine. It contains the base manual; separate model-year supplements are not included.

Supplied as one 123-page PDF in English.

• Engine repair: Engine removal and installation, top-end and crankcase teardown, crankshaft inspection, bearing and seal service, and recoil-starter repair.

• Carburetion and Autolube: Mikuni B38-34 carburetor overhaul, altitude and temperature jetting charts, oil-pump stroke checks, control-cable adjustment, and bleeding.

• Clutch and chain drive: Sheave alignment, primary and secondary clutch service, engagement and shift-speed tuning, V-belt inspection, and chain-case overhaul.

• Suspension and chassis: Slide-rail removal, track replacement and alignment, disc-brake service, steering adjustment, and ski inspection.

• Electrical diagnosis: CDI troubleshooting, ignition timing, spark-gap and coil tests, lighting checks, plus EC340G charging-system and electric-starter service.

• Assembly diagrams: 14 exploded-view diagrams detailing engine, powertrain, suspension, and chassis assemblies, plus separate EC340G and ET340TG wiring and routing diagrams.

The repair procedures are suited to experienced snowmobile mechanics with the specified pullers, measuring tools, and electrical testers.

Model Identification and Service Specifications

Identification tables list starting frame and engine numbers for each variant. The EC340G has recoil and electric starting; the ET340TG uses recoil starting. Their clutch settings, final-drive gearing, and track-deflection specifications are distinguished throughout the relevant sections.

Factory-recommended maintenance intervals and lubrication schedules cover routine and seasonal service. Reference tables provide cylinder bore and taper limits, piston and crankshaft clearances, tightening torques, secondary-clutch spring preload, chain-case oil capacity, and electrical test specifications.

Engine Repair and Autolube Service

Internal engine coverage includes piston-pin and small-end bearing inspection, cylinder wear measurement, crankshaft runout checks, and bearing and labyrinth-seal positioning during crankcase assembly. The engine-removal section identifies components that can be serviced with the engine still installed.

Autolube procedures cover pump-drive inspection, minimum and maximum stroke measurement, shim adjustment, and oil-system bleeding. The appendix’s Top End and Oil Pump/Oil Pump Drive Gear exploded views identify lubrication and sealing locations.

Mikuni Carburetor Tuning and Fuel Diagnosis

Carburetor service covers float-valve inspection and float-height adjustment, with separate low-speed and midrange/high-speed tuning sections. Temperature and altitude main-jet charts accompany troubleshooting tables for hard starting, poor acceleration, overflow, and excessive fuel consumption.

Carburetor repair cautions explain the risk of engine damage when tuning without the air silencer installed.

Clutch, Track, and Chassis Repair

Primary-sheave inspection reaches the bushings, slider buttons, spider levers, and weights. Secondary-sheave procedures cover ramp-shoe wear and spring preload; installation notes flag the risk of damaging the chain-case oil-seal lip.

Clutch-setting charts distinguish standard and high-altitude setups. The special-tool table identifies the primary sheave subassembly tool 90890-01858-00 / YS-91060 and sheave gauge 90890-01702-00 / YS-91047-3.

Track and chassis coverage extends to drive-axle sprocket positioning, hyfax wear, suspension spring and stopper-band adjustment, brake-pad and disc inspection, and steering toe-out. Primary Sheave and Slide Rail exploded views add assembly and lubrication references.

Review the manual’s safety precautions for fuel spills, battery handling, and the pressurized suspension shock before beginning service.

CDI, Charging, and Starter Diagnosis

Ignition flowcharts cover weak or missing spark and an engine that will not pick up speed, linking symptoms to coil tests and timing checks. This helps narrow an ignition fault before replacement parts are selected.

The EC340G sections cover rectifier and starter-relay testing, charging-output checks, and starter-motor inspection and repair, including the armature, commutator, pinion, and brushes. Separate Hitachi and Toyo Denso ignition-coil test data is also provided.

PDF Navigation and Readability

Page breakdown: The total comprises one added seller cover, 119 pages of chapters and reference material, one spark-plug photo sheet, and two oversized routing sheets. The 119-page portion includes the contents pages and one memo page. The spark-plug photographs are black and white.

Navigation: Embedded PDF bookmarks cover all seven chapters and many subsections.

Text search: Technical pages are not searchable; only added seller text can be searched.

Wiring readability: Small wire-color codes and dense routing labels require zooming.