Yamaha T25Y 1996-2000 Outboard Motor Supplementary Service Manual
Yamaha Models Covered & Key Technical Specifications
Models: Yamaha T25Y, FT25BED, FT25BET, T25ER, T25TR
Sub-models / Variants: 4-stroke OHC In-line, L (long shaft), X (extra-long shaft), Remote control, Power trim and tilt (ET/TR), ED/ER (Manual trim variants)
Model Years: 1996–2000
Serial Numbers: L: 810101-, X: 855101-, L: 840101-, X: 885101-
Technical Data:
- Engine displacement: 498 cc
- Configuration: 2-cylinder, 4-stroke OHC in-line
- Maximum output: 18.4 kW (25 HP) at 5,500 r/min
- Full throttle range: 5,000–6,000 r/min
- Compression pressure: 1,180–1,250 kPa
- Gear ratio: 2.42 (29/12)
- Starter motor output: 1.1 kW
- Ignition timing: 7.5–30.0 ± 3 degrees BTDC
Yamaha Manual Features & Content Preview
- Covers 1996–2000 Yamaha T25Y and related FT25BED/FT25BET outboard motor variants, including long and extra-long shaft models with remote control or power trim and tilt.
- Official 795-page Yamaha supplementary service publication (LIT-18616-02-20, first edition February 2000).
- Contains 47 exploded-view assembly diagrams and 18 technical system illustrations.
- Serves as the required extension for the F25X base service reference, detailing essential modifications and additional data exclusively for the T25Y series.
Technical Documentation Details
This technical guide maps out maintenance and assembly specifications for the Yamaha T25Y outboard series. It opens with identification markers, special tool requirements, and general specifications. Extensive chapters then cover periodic inspection and adjustments. Working on marine engines demands high caution. When reviewing and applying the procedures outlined in these sections, technicians must observe standard workshop safety protocols and handle marine fluids with appropriate protective gear. Further manual segments focus tightly on the power unit, lower unit, bracket unit, and electrical system. You will find clear assembly sequences for critical components. These include the camshaft, valves, water pump, and the shift rod assembly.
Precision Data and Reference Values
Included technical tables define torque specifications for fasteners ranging from M5 to M16. You will find these values provided in Nm, m•kgf, and ft-lb units. The manual documents compression pressure at 1,180–1,250 kPa. It also specifies ignition timing between 7.5–30.0 degrees BTDC. Engine lubrication requirements list SAE #90 gear oil for the lower unit, while 4-stroke engine oil grades 10W-30 through 20W-40 are required for the power unit. Testing sections detail peak voltage reference values for charging, ignition, and enrichment control systems. Finally, cold temperature valve clearances are specified at 0.2 ± 0.05 mm for the intake and 0.3 ± 0.05 mm for the exhaust.
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