Yamaha 60 / 70 / 75 / 90 two-stroke (6H2) service guide
Oil, gear oil, spark plugs and the service schedule for the Yamaha 60 / 70 / 75 / 90 two-stroke (6H2) (50 to 90 hp, two-stroke), from the factory service manual, plus how we service it in Hawaiʻi.
Models covered: 3 cylinder two-strokes, three carburetors. 50, 60 and 70 hp: 849 cm³ (51.8 cu in), 72.0 x 69.5 mm. 75, 80 and 90 hp: 1,141 cm³ (69.6 cu in), 82.0 x 72.0 mm. LIT-18616-02-66: 60TR code 6H2 from L:1003093; 70TR code 6H3 from L:1002818; 90TR code 6H1 from L:1007591; all three oil injected. 6H2-28197-Z9-11, USA or Canada name: code 62F: 50GETO L:400805. Code 6H2: P60TH (60FEHTO) L:551924, X:750186; C60ER, Canada (60FED) S:001118, L:305624; 60FEDO S:100850, L:407212; C60TR (60FET) S:050474, L:357665, X:710231; 60FETO S:150756, L:472180, X:732000. Code 6H3: 70BEDO L:402029; 70TR (70BETO) L:491824, X:731262. Code 6H0: C75TR (75CET) L:001251; 75TR, Canada (75CETO) L:951540; P75TH (75CEHTO) L:900371; 80AETO L:457543, X:851331. Code 6H1: 90AEHD L:320132; 90AED L:401108; C90TR (90AET) L:354053; 90TR / B90TR (90AETO) L:498690, X:856313. oil injection on the rest.
Quick answers
- What two-stroke oil does a Yamaha 60 / 70 / 75 / 90 two-stroke use?
- 2-stroke outboard motor oil (TC-W3; YAMALUBE two-cycle outboard motor oil recommended in USA). Oil injected models: oil tank 2.8 L (2.96 US qt, 2.46 Imp qt) on 50, 60, 70 hp; 3.3 L (3.49 US qt, 2.90 Imp qt) on 75, 80, 90 hp.
- What is the fuel to oil ratio for a Yamaha 60 / 70 / 75 / 90 two-stroke?
- Oil injected models (60TR, 70TR, 90TR and others): oil is fed by the injection pump.
- What gear oil does a Yamaha 60 / 70 / 75 / 90 two-stroke use, and how much?
- GEAR CASE LUBE, SAE 90 (6H2-28197-Z9-11: hypoid gear oil SAE #90, GEAR CASE LUBE recommended in USA). Quantity: 60, 70, 75, 80, 90 hp: 610 cm³ (20.62 US oz, 21.51 Imp oz). 50 hp: 500 cm³ (16.91 US oz, 17.60 Imp oz). Fill through the oil plug hole until oil flows out of the level plug hole.
- What spark plug does a Yamaha 60 / 70 / 75 / 90 two-stroke use?
- 60, 70, 75, 80, 90 hp: NGK B8HS-10 (BR8HS-10 for Canada, Europe, China and South Africa); 50 hp: BR8HS-10; qty 3. Gap: 0.9 to 1.0 mm (0.035 to 0.039 in).
- How often should a Yamaha 60 / 70 / 75 / 90 two-stroke be serviced?
- The factory schedule lists: Initial 10 hours (break-in); 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 60 / 70 / 75 / 90 two-stroke?
- 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 60 / 70 / 75 / 90 two-stroke?
- 800 ± 50 r/min.
- What is the propeller nut torque on a Yamaha 60 / 70 / 75 / 90 two-stroke?
- 35 N·m (3.5 m·kg, 25 ft·lb); if the nut does not line up with the cotter pin hole, turn it in further.
Maintenance specs
| Two-stroke engine oil | 2-stroke outboard motor oil (TC-W3; YAMALUBE two-cycle outboard motor oil recommended in USA). Oil injected models: oil tank 2.8 L (2.96 US qt, 2.46 Imp qt) on 50, 60, 70 hp; 3.3 L (3.49 US qt, 2.90 Imp qt) on 75, 80, 90 hp |
|---|---|
| Fuel to oil ratio | Oil injected models (60TR, 70TR, 90TR and others): oil is fed by the injection pump |
| Gear oil | GEAR CASE LUBE, SAE 90 (6H2-28197-Z9-11: hypoid gear oil SAE #90, GEAR CASE LUBE recommended in USA) |
| Gear oil quantity | 60, 70, 75, 80, 90 hp: 610 cm³ (20.62 US oz, 21.51 Imp oz). 50 hp: 500 cm³ (16.91 US oz, 17.60 Imp oz). Fill through the oil plug hole until oil flows out of the level plug hole |
| Gear oil filling (drain) plug and oil level plug | Draining: remove the oil filling plug first. Filling: secure the level (check) plug first, then the filling plug |
| Lower unit holding pressure | 100 kPa (1.0 kg/cm², 14.2 psi) at the oil level hole with the drain screw tight, gear case in a water tank, must hold 10 seconds; do not overpressurize |
| Spark plug | 60, 70, 75, 80, 90 hp: NGK B8HS-10 (BR8HS-10 for Canada, Europe, China and South Africa); 50 hp: BR8HS-10; qty 3 |
| Spark plug gap | 0.9 to 1.0 mm (0.035 to 0.039 in) |
| Spark plug torque (M14) | 25 N·m (2.5 m·kg, 18 ft·lb) |
| Idle speed | 800 ± 50 r/min |
| Thermostat | Opens at 48 to 52 °C (118 to 126 °F); fully open at 60 °C (140 °F); valve lift 3 mm (0.12 in) |
| Anode | Inspect; replace if worn out. If scaled, remove, wire brush, clean off oil and grease, polish the mounting contact surfaces and reinstall. Never paint it. |
| Propeller nut (M16) | 35 N·m (3.5 m·kg, 25 ft·lb); if the nut does not line up with the cotter pin hole, turn it in further |
| Power trim and tilt fluid (PTT models) | ATF (automatic transmission fluid). Fluid level plug: long transom unit [6H1-15, 62F-02] 7 N·m (0.7 m·kg, 5.1 ft·lb); short transom unit [6H308] 3 N·m (0.3 m·kg, 2.2 ft·lb). Check tilted up and locked: level just below the hole |
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 (break-in)
Replace: gear case oil, gear case plug gaskets, propeller cotter pin
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: gear case oil, gear case plug gaskets, propeller cotter pin
Check: spark plugs, fuel filter, anodes
Every 200 hours (1 year)
Replace: gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller
Check: spark plugs, fuel filter, 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 60C, 70C, 90C service manual LIT-18616-02-66. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.