Yamaha F115 / LF115 service guide
Oil, gear oil, spark plugs and the service schedule for the Yamaha F115 / LF115 (115 hp, four-stroke), from the factory service manual, plus how we service it in Hawaiʻi.
Models covered: F115TR and LF115TR four-strokes, 4 cylinder 1.74 L, fuel injected. F115TR model code 68V from serial 1066827; LF115TR 68W from 1002955.
Quick answers
- How much oil does a Yamaha F115 / LF115 take?
- 4.3 L (4.55 US qt, 3.78 Imp qt) without filter; 4.5 L (4.76 US qt, 3.96 Imp qt) with filter.
- What engine oil does a Yamaha F115 / LF115 use?
- 4-stroke motor oil, API SE, SF, SG, SH, SJ or SL, SAE 5W-30, 10W-30 or 10W-40.
- What gear oil does a Yamaha F115 / LF115 use, and how much?
- Hypoid gear oil, API GL-4, SAE 90. Quantity: F115: 760 cm³ (25.7 US oz, 26.8 Imp oz); LF115: 715 cm³ (24.2 US oz, 25.2 Imp oz).
- What spark plug does a Yamaha F115 / LF115 use?
- NGK LFR6A-11, qty 4. Gap: 1.0 to 1.1 mm (0.039 to 0.043 in).
- How often should a Yamaha F115 / LF115 be serviced?
- The factory schedule lists: Initial 10 hours (1 month); Initial 50 hours (3 months); Every 100 hours (6 months); Every 200 hours (1 year); Every 500 hours (2.5 years); Every 1,000 hours (5 years). 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 F115 / LF115?
- The factory schedule says to inspect it at 200 hours and 1,000 hours. 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 F115 / LF115?
- 700 to 800 r/min (after 5 minutes warm up).
- What is the propeller nut torque on a Yamaha F115 / LF115?
- M18: 54 N·m (5.4 kgf·m, 39.8 ft·lb).
Maintenance specs
| Engine oil | 4-stroke motor oil, API SE, SF, SG, SH, SJ or SL, SAE 5W-30, 10W-30 or 10W-40 |
|---|---|
| Engine oil quantity | 4.3 L (4.55 US qt, 3.78 Imp qt) without filter; 4.5 L (4.76 US qt, 3.96 Imp qt) with filter |
| Oil filter | 18 N·m (1.8 kgf·m, 13.3 ft·lb) with a 64 mm (2.5 in) oil filter wrench; oil the new O-ring |
| Engine oil drain bolt | M14: 27 N·m (2.7 kgf·m, 19.9 ft·lb) |
| Gear oil | Hypoid gear oil, API GL-4, SAE 90 |
| Gear oil quantity | F115: 760 cm³ (25.7 US oz, 26.8 Imp oz); LF115: 715 cm³ (24.2 US oz, 25.2 Imp oz) |
| Gear oil drain and check screws | 9 N·m (0.9 kgf·m, 6.6 ft·lb), new gaskets |
| Lower unit holding pressure | 70 kPa (0.7 kgf/cm², 10 psi), held at least 10 seconds, through the check screw hole |
| Spark plug | NGK LFR6A-11, qty 4 |
| Spark plug gap | 1.0 to 1.1 mm (0.039 to 0.043 in) |
| Spark plug torque | 25 N·m (2.5 kgf·m, 18.4 ft·lb) |
| Idle speed | 700 to 800 r/min (after 5 minutes warm up) |
| Thermostat | Opens (0.05 mm lift) 48 to 52 °C (118 to 126 °F); above 60 °C (140 °F) lift more than 4.3 mm (0.17 in); new gasket |
| Anode screw (exhaust cover anodes) | M4: 3 N·m (0.3 kgf·m, 2.2 ft·lb) |
| Propeller nut | M18: 54 N·m (5.4 kgf·m, 39.8 ft·lb) |
| Power trim and tilt | Fluid ATF Dexron II, filled to overflow at the filler hole, tilted full up; reservoir cap 0.7 N·m (0.07 kgf·m, 0.5 ft·lb), new O-ring. Trim tab bolt M10 42 N·m (4.2 kgf·m, 31.0 ft·lb) |
| Valve clearance, cold | IN 0.20 ± 0.03 mm (0.0079 ± 0.0012 in); EX 0.34 ± 0.03 mm (0.0134 ± 0.0012 in) |
| Timing belt | Turn the flywheel clockwise and check inside and outside; replace if cracked, damaged or worn (no deflection spec). |
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 (1 month)
Replace: gear case oil, gear case plug gaskets
Check: engine oil level, spark plugs, fuel filter
Initial 50 hours (3 months)
Replace: gear case plug gaskets, propeller cotter pin
Check: 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: fuel filter, anodes
Every 200 hours (1 year)
Replace: engine oil, oil filter, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: spark plugs, fuel filter, thermostat, anodes
Every 500 hours (2.5 years)
Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: fuel filter, anodes
Every 1,000 hours (5 years)
Replace: engine oil, oil filter, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: spark plugs, 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 F115 / LF115 service manual, LIT-18616-02-98. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.