Segment:
Vintage Yamaha Snowmobiles (early to mid-1970s era).
Comparison:
This era saw Yamaha competing with brands like Ski-Doo, Arctic Cat, and Polaris in the growing snowmobile market. The GPX series was known for its performance and reliability for its time.
Manual Advantage:
Provides essential, detailed technical information for maintaining and repairing these classic Yamaha snowmobiles, crucial for enthusiasts preserving these vintage machines.
Digital Benefit:
Instant access via PDF download, allowing for on-trail or in-shop use on digital devices, printed as needed, and protected by a lifetime replacement policy.
Covered Machines:
All versions of 1973 Yamaha GPX338F, 1973 Yamaha GPX433F, 1974 Yamaha GPX338F, 1974 Yamaha GPX433F, 1975 Yamaha GPX338F, 1975 Yamaha GPX433F Snowmobiles
Estimated Page Count:
Estimated based on typical repair manuals for this era and complexity; likely 200-400 pages.
Type:
Comprehensive Repair Manual, also containing information akin to Owner's Manuals and Parts Catalogs.
Format:
Digital PDF Download
Engine:
Complete engine disassembly, assembly, inspection, repair, and tuning for both 338cc and 433cc models. Includes detailed specifications.
Fuel System:
Carburetor identification, adjustment, cleaning, overhaul, fuel pump operation, fuel line maintenance.
Lubrication Cooling:
Lubrication system design, oil recommendations, cooling system operation (air-cooled specifications if applicable), coolant (if liquid-cooled).
Transmission Drive:
Drive clutch, driven clutch, primary and secondary clutch service, belt inspection and replacement, chain drive system, sprockets, lubrication.
Steering Suspension:
Steering system components, linkage, bushings, skis, ski carbides, shock absorber inspection, service, and replacement.
Electrical System:
Ignition system (CDI, points, coils), lighting, battery charging system, starter system (if applicable), wiring diagrams, troubleshooting.
Bodywork Chassis:
Body panel removal/installation, seat, handlebars, controls, chassis components, general upkeep.
Intake Exhaust:
Airbox, intake manifold, exhaust system components, mufflers, tuning for optimal performance.
Routine Maintenance:
Detailed procedures for all scheduled maintenance tasks, including lubrication, inspection, adjustments, and cleaning.
Engine Rebuild:
Complete step-by-step instructions for engine disassembly, component inspection, machining recommendations, reassembly, and initial startup.
Troubleshooting:
Systematic diagnostic procedures for common and advanced problems, including symptoms, causes, and corrective actions.
Component Replacement:
Detailed instructions for replacing individual components across all systems, from minor parts to major assemblies.
Depth:
Comprehensive. Covers basic maintenance to in-depth engine and component overhauls. Suitable for DIY mechanics and professional technicians.
Gp 338F Engine:
338cc (approximate displacement, likely twin-cylinder, 2-stroke, air-cooled).
Gp 433F Engine:
433cc (approximate displacement, likely twin-cylinder, 2-stroke, air-cooled).
Horsepower 338:
Estimated 30-35 HP range for the 338cc. (Exact figures vary by tune and year).
Horsepower 433:
Estimated 40-45 HP range for the 433cc. (Exact figures vary by tune and year).
Carburetor Type:
Likely dual Mikuni carburetors (specific models to be detailed in manual).
Fuel Type:
Leaded or unleaded gasoline mixed with 2-stroke oil (specific ratio in manual).
Ignition System:
CDI (Capacitor Discharge Ignition) or breaker points ignition system depending on exact sub-model and year.
Type:
Automatic CVT (Continuously Variable Transmission) driven by centrifugal clutches (primary and secondary).
Options:
No manual transmission options typically for this type of snowmobile.
Clutch Service:
Detailed procedures for clutch alignment, weight tuning, spring replacement, and roller inspection.
Drive System:
Chain drive to the track (specific gear reduction ratios to be detailed).
Certification:
Not applicable for modern safety rating systems of the era. Focus is on mechanical reliability and operational safety guidelines.
Controls:
Handlebar steering, throttle lever, brake lever, kill switch.
Protection:
Chassis integrity, seat design, running boards for foot placement.
General Schedule:
Specific intervals for checking/changing spark plugs, cleaning air filters, inspecting belts, checking lubrication, and clutch maintenance. (Detailed in manual).
Engine Oil:
Yamaha recommends specific 2-stroke oil mixes. (Exact type and ratio provided in manual).
Gearbox Oil:
Yamaha GL-4 or equivalent gear oil for the chaincase. (Specific viscosity and capacity in manual).
Common Problems:
Wear on clutch rollers and buttons, carburetor jetting issues due to fuel changes over time, seal degradation, track wear, and ignition coil failures are common in vintage machines of this era. The manual will provide diagnostic steps.
Yamaha Legacy:
Yamaha has a long history in powersports, establishing itself as a manufacturer of reliable and performance-oriented vehicles since its inception.
Gpx Series:
The GPX series represented Yamaha's push into the performance segment of the snowmobile market in the 1970s, offering more powerful and refined models compared to earlier utility-focused machines.
Manufacturing Period:
Produced between 1973 and 1975. These models were part of the rapid evolution of snowmobile technology during the 1970s.
