Yamaha F2.5 (F2.5C) service guide
Oil, gear oil, spark plugs and the service schedule for the Yamaha F2.5 (F2.5C) (2.5 hp, four-stroke), from the factory service manual, plus how we service it in Hawaiʻi.
Models covered: F2.5MH four-stroke, single cylinder OHV, 72 cm³, tiller, manual start, splash lubrication, TCI ignition. Model code 69M, starting serial S: 1011798.
Quick answers
- How much oil does a Yamaha F2.5 take?
- 0.35 L (0.09 US gal, 0.08 Imp gal); check level through the oil level window.
- What engine oil does a Yamaha F2.5 use?
- 4-stroke motor oil, API SE, SF, SG, SH or SJ, SAE 10W-30 or 10W-40.
- What gear oil does a Yamaha F2.5 use, and how much?
- GEAR CASE LUBE, SAE 90. Quantity: 75 cm³ (2.5 US oz, 2.6 Imp oz).
- What spark plug does a Yamaha F2.5 use?
- NGK BR6HS. Gap: 0.6 to 0.7 mm (0.024 to 0.028 in).
- How often should a Yamaha F2.5 be serviced?
- The factory schedule lists: Initial 10 hours; Initial 50 hours (3 months); Every 100 hours (6 months); Every 200 hours (1 year). In Hawaiʻi's salt water we do a full yearly service every 200 hours or 1 year, whichever comes first, and a new engine needs its first (break-in) service.
- When should the water pump impeller be replaced on a Yamaha F2.5?
- The factory schedule gives no replacement interval. In Hawaiʻi's warm salt water we replace it every 200 hours or 1 year, whichever comes first, because a worn impeller is the most common cause of overheating.
- What is the idle speed of a Yamaha F2.5?
- 1,800 to 2,000 r/min.
Maintenance specs
| Engine oil | 4-stroke motor oil, API SE, SF, SG, SH or SJ, SAE 10W-30 or 10W-40 |
|---|---|
| Engine oil quantity | 0.35 L (0.09 US gal, 0.08 Imp gal); check level through the oil level window |
| Engine oil drain bolt | 18 N·m (1.8 kgf·m, 13.3 ft·lb) |
| Gear oil | GEAR CASE LUBE, SAE 90 |
| Gear oil quantity | 75 cm³ (2.5 US oz, 2.6 Imp oz) |
| Gear oil screw | 8.5 N·m (0.9 kgf·m, 6.3 ft·lb) |
| Lower unit holding pressure | 100 kPa (1.0 kgf/cm², 14 psi) for at least 10 seconds |
| Spark plug | NGK BR6HS |
| Spark plug gap | 0.6 to 0.7 mm (0.024 to 0.028 in) |
| Spark plug torque | 25 N·m (2.5 kgf·m, 18.4 ft·lb) |
| Idle speed | 1,800 to 2,000 r/min |
| Thermostat | Opens 48 to 52 °C (118 to 126 °F); fully open 60 °C (140 °F); lift at least 3 mm (0.12 in) |
| Anode screw | 2.0 N·m (0.2 kgf·m, 1.5 ft·lb) |
| Valve clearance, cold | Intake and exhaust 0.08 to 0.12 mm (0.0031 to 0.0047 in); rocker arm locknut 10 N·m (1.0 kgf·m, 7.4 ft·lb) |
Service schedule
The factory maintenance intervals, with what is replaced and what is checked at each. Rows marked Hawaiʻi are our shop's yearly service for salt water use.
Initial 10 hours
Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets
Check: spark plugs, fuel filter
Initial 50 hours (3 months)
Replace: gear case plug gaskets, propeller cotter pin
Check: spark plugs, fuel filter, anodes
Every 100 hours (6 months)
Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin
Check: spark plugs, fuel filter, anodes
Every 200 hours (1 year)
Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: spark plugs, fuel filter, thermostat, anodes
We replace the water pump impeller at every service from 200 hours up, which can be sooner than the factory schedule, because of Hawaiʻi’s warm salt water.
Source: Yamaha F2.5C service manual, LIT-18616-02-54. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.