Yamaha 50G-90A Outboard Service Manual (P/N LIT-18616-01-39)
1333 Pages • 63.00 MB • Instant, Printable PDF
Yamaha Models Covered & Key Technical Specifications
Models: 50G, 60F, 70B, 75C, 80A, 90A, P60U, C60U, 70U, P75U, 90U, 50GEO, 50GETO, 60FE, 60FEO, 60FET, 60FETO, 60FEMO, 70BEO, 70BETO, 75CEHTO, 75CETO, 80AEO, 80AETO, 90AEO, 90AETO, C60ER, C60TR, P60TH, 70TR, P75TH, 90TR
Sub-models / Variants: Manual control, Remote control, Manual tilt, Power trim and tilt, 2-stroke, L (long), UL (ultra-long), S (short)
Trade Names: Yamaha Marine Outboards
Model Years: 1995–2006
Serial Numbers: S: 100212~ / L: 400787~ (50GEO), S: 200181~ / L: 501521~ (50GETO), S: 001043~ / L: 305096~ (60FE/C60ER), S: 050454~ / L: 352257~ (60FET/C60TR), S: 100825~ / L: 406709~ (60FEO), S: 150688~ / L: 467727~ / UL: 731661~ (60FETO), L: 551339~ (P60TH), S: 100216~ / L: 401862~ (70BEO), S: 150366~ / L: 487236~ / UL: 731037~ (70BETO/70TR), L: 900101~ (P75TH), L: 950101~ (75CETO), L: 401108~ (80AEO), L: 457240~ / UL: 850891~ (80AETO), L: 401086~ (90AEO), L: 491155~ / UL: 855248~ (90AETO/90TR)
Technical Data:
- Engine type: 3-cylinder, 2-stroke
- Engine displacement: 849 cc (50-70 hp), 1141 cc (75-90 hp)
- Full throttle RPM range: 4500–5500 RPM (50-80 hp), 5000+ RPM (90 hp)
- Idle speed: 800 ± 50 RPM
- Ignition system: C.D.I. (Capacitor Discharge Ignition)
- Spark plug gap: 0.9–1.0 mm (0.035–0.039 in)
- Gear ratio: 14:24 (50 hp), 12:28 (60-70 hp), 13:26 (75-90 hp)
- Fuel: Regular gasoline (min. 86 octane)
- Engine oil: TC-W3
- Gear oil: Hypoid gear oil SAE #90
- Battery capacity: 70 Ah (252 kC)
Yamaha Manual Features & Content Preview
- Covers 1995–2006 Yamaha 50G through 90A series 2-stroke outboards, including P60U, C60U, 70U, P75U, 90U, and remote-control or power trim variants
- Official 1,333-page Yamaha publication (P/N 6H2-28197-Z5-11, first edition September 1995)
- Contains 47 detailed exploded-view diagrams, 13 electrical wiring charts, and 5 comprehensive torque-specification tables
- Acts as the base factory reference documenting the transition from earlier 2-cylinder to the 3-cylinder engine layouts found in these specific models
Workshop Application and Content Overview
When dealing with complex overhauls, having immediate access to exact factory specifications keeps your bays moving. This service documentation provides comprehensive reference material for these 2-stroke outboard units rather than generic guidance. Major chapters detail engine power head removal, complete lower unit disassembly, ignition system calibration, and fuel injection adjustments. Every component group receives dedicated analysis sections. You will find specific inspection criteria for the reed valve, thermostat, and oil injection pump drive gears, alongside dedicated troubleshooting flow charts. This covers the engine, fuel, electrical, and power trim systems completely.
Precision Data and Reference Tables
The manual includes the essential specifications required to verify tolerances for the 50G through 90A series engines. For example, the cylinder head warpage limit for all models is strictly specified at 0.1 mm. Piston-to-cylinder clearance for the 50–70 hp series sits at 0.050–0.055 mm, while ignition timing for 90 hp units at full advanced is documented at 22° ± 1° BTDC. Working on marine engines involves high-pressure fuel systems and heavy components, so always adhere to standard shop safety protocols and verify your own technical competency before diving into heavy maintenance. This documentation serves as your primary reference for those exact fluid capacities, bolt torque values, and electrical resistance measurements for the charging, pulser, and ignition coils.
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