Yamaha F9.9 (F9.9F) / T9.9 (T9.9G) service guide
Oil, gear oil, spark plugs and the service schedule for the Yamaha F9.9 (F9.9F) / T9.9 (T9.9G) (9.9 hp, four-stroke), from the factory service manual, plus how we service it in Hawaiʻi.
Models covered: F9.9FMH, T9.9GEH, T9.9GPH, T9.9GPR. Four-stroke 2 cylinder, 212 cm³, carburetor, CDI (micro computer). F9.9F model code 6AU from 1000001; T9.9G (High Thrust) model code 6AV from 1000001.
Quick answers
- How much oil does a Yamaha F9.9 / T9.9 take?
- 0.8 L (0.85 US qt, 0.70 Imp qt).
- What engine oil does a Yamaha F9.9 / T9.9 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 F9.9 / T9.9 use, and how much?
- Hypoid gear oil, API GL-4, SAE 90. Quantity: F9.9FMH 150 cm³ (5.07 US oz, 5.29 Imp oz); T9.9G 370 cm³ (12.51 US oz, 13.05 Imp oz).
- What spark plug does a Yamaha F9.9 / T9.9 use?
- NGK BR6HS-10. Gap: 0.9 to 1.0 mm (0.035 to 0.039 in).
- How often should a Yamaha F9.9 / T9.9 be serviced?
- The factory schedule lists: Initial 20 hours (3 months); Every 100 hours (1 year); Every 300 hours (3 years); Every 500 hours (5 years); Every 1,000 hours. 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 F9.9 / T9.9?
- The factory schedule says to replace it at 300 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 F9.9 / T9.9?
- 1,050 ± 50 r/min.
- What is the propeller nut torque on a Yamaha F9.9 / T9.9?
- 17 N·m (1.7 kgf·m, 12.5 ft·lb); high thrust model 21 N·m (2.1 kgf·m, 15.5 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 | 0.8 L (0.85 US qt, 0.70 Imp qt) |
| Engine oil filter | No spin-on filter. |
| Engine oil drain bolt | 24 N·m (2.4 kgf·m, 17.7 ft·lb) |
| Gear oil | Hypoid gear oil, API GL-4, SAE 90 |
| Gear oil quantity | F9.9FMH 150 cm³ (5.07 US oz, 5.29 Imp oz); T9.9G 370 cm³ (12.51 US oz, 13.05 Imp oz) |
| Gear oil drain and check screws | 9 N·m (0.9 kgf·m, 6.6 ft·lb) |
| Lower unit holding pressure | 100 kPa (1.0 kgf/cm², 14 psi) |
| Spark plug | NGK BR6HS-10 |
| Spark plug gap | 0.9 to 1.0 mm (0.035 to 0.039 in) |
| Spark plug torque | 24 N·m (2.4 kgf·m, 17.7 ft·lb) |
| Idle speed | 1,050 ± 50 r/min |
| Thermostat | Opens 58 to 62 °C (136 to 144 °F) at 0.05 mm; fully open 70 °C (158 °F); lift more than 3.0 mm (0.12 in) |
| Anodes | Anode screw M5 2 N·m (0.2 kgf·m, 1.5 ft·lb); lower unit anode bolt M6 8 N·m (0.8 kgf·m, 5.9 ft·lb); anode plug 18 N·m (1.8 kgf·m, 13.3 ft·lb) |
| Propeller nut | 17 N·m (1.7 kgf·m, 12.5 ft·lb); high thrust model 21 N·m (2.1 kgf·m, 15.5 ft·lb) |
| PT unit (PT models) | Fluid ATF Dexron II; reservoir cap 5 N·m (0.5 kgf·m, 3.7 ft·lb) |
| Valve clearance, cold | Intake 0.15 to 0.20 mm (0.006 to 0.008 in); exhaust 0.20 to 0.25 mm (0.008 to 0.010 in); rocker arm locknut 7 N·m (0.7 kgf·m, 5.2 ft·lb) |
| Timing belt | Check every 100 hours (1 year), replace if cracked, damaged or worn; replace at 1,000 hours. Turn the flywheel clockwise only. |
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 20 hours (3 months)
Replace: engine oil, oil drain plug gasket, gear case oil, gear case plug gaskets, propeller cotter pin
Every 100 hours (1 year)
Replace: engine oil, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin
Check: oil filter, spark plugs, water pump impeller, thermostat, anodes
Every 200 hours or 1 year (our Hawai‘i yearly service) Hawai‘i
Replace: engine oil, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: oil filter, spark plugs, thermostat, anodes
Every 300 hours (3 years)
Replace: engine oil, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: oil filter, spark plugs, thermostat, anodes
Every 500 hours (5 years)
Replace: engine oil, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: oil filter, spark plugs, thermostat, anodes
Every 1,000 hours
Replace: engine oil, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: oil filter, 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 F9.9/T9.9 service manual, LIT-18616-03-03. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.