Yamaha · Outboard

Yamaha F15C / F20B

The F15C and F20B are Yamaha’s 362 cc two-cylinder four-strokes with a belt-driven overhead camshaft, one carburettor with Prime Start, CDI ignition and a spin-on oil filter, introduced in 2006 and still in production. Yamaha Europe also sells the same engine as the F9.9H, and its 2026 manual simply calls the range F15 and F20; at 51–61 kg they are common on tenders, RIBs and small fishing boats, and with the 20 in shaft on small yachts. The part numbers below were checked in F15C, F20B and US carburettor F15/F20 catalogues, so on an F9.9H confirm them with your dealer. The fuel-injected F20G and US F20 EFI (432 cc) and the 212 cc F9.9J, which has its own page here, are different engines with other parts.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
On the marketplace

Manuals & documents

The links go straight to Yamaha. We host no manuals or drawings — the manufacturer’s copy is the current one.

Owner’s manual F9.9H, F15, F20 (6AG-28199-7K-E0, European edition 2026) Operation manual cdn2.yamaha-motor.eu · PDF · EN
Owner’s manual F9.9H, F15C, F20B (6AG-28199-77-E0, European edition 2012) Operation manual cdn2.yamaha-motor.eu · PDF · EN
Owner’s manual F15C, F20B, 2026 model year (6AG-28199-0L, Japanese) Operation manual www2.yamaha-motor.co.jp · PDF · JA
Owner’s manual F15C, F20B, first edition for the 2007 model year (6AG-28199-00, Japanese) Operation manual www2.yamaha-motor.co.jp · PDF · JA
Yamaha Motor Europe owner’s manual library (search by model, year or manual number) Manual portal yamaha-motor.eu · EN
Yamaha Motor Japan: outboard owner’s manuals since 2000 (F15C/F20B 2007–2026 under 9–20 hp; Japanese) Manual portal www2.yamaha-motor.co.jp · JA
Yamaha Outboards (US): owner’s manuals by model prefix, shaft length and serial number Manual portal yamahaoutboards.com · EN
Yamaha’s official manual store: printed and PDF owner’s and service manuals Manual portal yamahapubs.com · EN

Wear parts & part numbers

Part	OEM number	Also fits	Note
Water pump repair kit	`6AH-W0078-02-00`^1,2,3,4,5	—	Impeller 63V-44352-01, pump housing 6AH-44311-00, cartridge insert 63V-44322-00, damper 6L2-44367-00, Woodruff key 664-44338-00, O-ring 93210-49046-00, outer plate 68T-44323-00 and plates 63V-44328-01. The 2021 European catalogues (F15CMH, F20BEP) list -02-00; catalogues up to about 2015 and US dealers list 6AH-W0078-00-00 for the same engines.
Raw water pump impeller	`63V-44352-01-00`^6,7,8,9	—	All F15C/F20B and the US carburettor F15/F20 (catalogues 2012–2021); also inside the pump kit. It is driven by Woodruff key 664-44338-00-00.
Engine oil filter	`5GH-13440-80-00`^1,2,10,11,12replaces 5GH-13440-61-00replaces 5GH-13440-50-00replaces 5GH-13440-20-00	—	Spin-on cartridge, tightened by hand to about 18 N·m. Older catalogues show -20 (US models 2008/2012) and -50 (2014/2015); the 2021 European catalogue lists -61, which dealers now supply as -80.
Spark plug	`94702-00418-00`^13,3,14	NGK `DPR6EB-9`^13,3	Yamaha’s European number for an NGK DPR6EB-9; US dealers sell the same plug as DPR-6EB90-00-00. Two per engine, gap 0.8–0.9 mm, 17 N·m.
Thermostat	`6AH-12411-00-00`^3,1,11,15,16	—	The same on F15C and F20B in every catalogue checked (2008–2021).
Thermostat gasket	`6AH-12414-00-00` · `688-12412-00-00`^3,12,11	—	Thermostat cover gasket 6AH-12414-00-00 and the thermostat seal underneath it, 688-12412-00-00.
Anode (engine)	`6G8-11325-00-00`^{3,12,17,11,18}	—	Small internal anode; the maintenance-parts list shows four per engine, two on the cylinder head and two on the block and thermostat-cover side.
Anode (engine)	`6E5-11325-00-00`^3,12,11	—	A fifth, different powerhead anode, held by a flat-head screw (cylinder/crankcase diagram).
Anode (lower unit)	`6AH-45251-00-00`^3,19,20,21	—	External anode on the gearcase above the propeller; all F15C/F20B and US carburettor F15/F20.
Anode (lower unit)	`65W-45251-00-00`²	—	On the clamp bracket of power-tilt models; found only in the maintenance-parts list of the 2021 F20BEP, not on manual-tilt tiller models. One source.
Fuel filter (engine)	`61N-24563-10-00`^3,22,23	—	Filter element inside the cup-type filter under the cowling; cup 61N-24521-00-00, O-ring 93210-32738-00.
Fuel filter (engine)	`61N-24560-10-00`^22,23	—	The complete cup-type filter.
Fuel pump	`6AH-24410-00-00`^22,23	—	Mechanical diaphragm pump; Yamaha schedules a check every 300 h or 3 years.
Timing belt	`6AH-46241-00-00`^24,25	—	Toothed camshaft belt (the catalogues call it ‘belt’ or ‘V-belt’); replace at 1000 h.
Drain plug gasket	`90430-14M09-00`^3,26,27	—	Engine oil drain screw gasket; fit a new one at every oil change. Drain screw 90340-14M06-00, 19.5 N·m.
Gear oil plug gaskets	`90430-08020-00`^3,28,8	—	Two per change, for the drain screw and the level plug (90340-08002-00). The 2021 European catalogue lists 90430-08003-00 in the same place.
Valve cover gasket	`6AH-11356-00-00`^17,29,30	—	Cylinder head cover seal (Yamaha: ‘seal, cylinder 2’); needed when the cover comes off for a valve-clearance check.
Gasket set	`6AG-W0001-00-00`^29,30	—	Powerhead gasket kit.
Lower unit seal kit	`6AH-W0001-20-00`^6,4	—	Lower unit gasket kit.
Carburettor repair kit	`6AH-W0093-01-00`^31,32	—	Gasket, needle valve, float pin and other small parts.
Propeller hardware kit	`90171-10M01-00` · `91490-30020-00`^19,20	—	Castle nut and cotter pin, with washer 90201-10M01-00 and spacer 6E7-45987-01-00. Tighten to 17 N·m and fit a new cotter pin every time the propeller has been off.
Propeller	`63V-45945-10-00`^19,20	—	3-blade aluminium, 9¼ × 9 in, the lowest pitch listed, for heavy boats; cupped according to the European catalogue. Pick the pitch that lets the engine reach 5000–6000 rpm at full throttle.
Propeller	`63V-45952-10-00`^19,20	—	3-blade aluminium, 9¼ × 10 in (J1).
Propeller	`63V-45943-10-00`^19,20	—	3-blade aluminium, 9¼ × 11 in; cupped according to the European catalogue.
Propeller	`63V-45941-10-00`^19,20	—	3-blade aluminium, 9¼ × 12 in (J1), the highest pitch listed.

Numbers checked against the sources below on 12 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

Task	Interval
First service	After the first 20 h or 3 months: change engine oil and gear oil; check the fuel filter, fuel lines, battery, idle speed, propeller and cotter pin; grease the greasing points¹³
Engine oil change	First after 20 h or 3 months, then every 100 h or yearly¹³
Oil filter	Every 100 h or yearly¹³
Gear oil change	First after 20 h or 3 months, then every 100 h or yearly¹³
Spark plug	Check or replace every 100 h or yearly¹³
Fuel filter	Check and clean or replace at 20 h, then every 100 h or yearly¹³
Raw water impeller	Impeller and pump housing: check every 100 h or yearly, replace every 300 h or 3 years¹³
Thermostat	Check every 100 h or yearly¹³
Fuel pump	Check or replace every 300 h or 3 years¹³
Anode	Outer anodes and the anodes on cylinder head and thermostat cover: check every 100 h or yearly; anodes on the exhaust cover, cooling-passage cover and rectifier/regulator cover: replace every 500 h or 5 years¹³
Timing belt	Check every 100 h or yearly; replace at 1000 h¹³
Valve clearance	Check and adjust every 500 h or 5 years (dealer)¹³
Lubrication	At 20 h, then every 100 h or yearly: water-resistant grease (Yamalube grease A) on pivots and linkages, corrosion-resistant grease (Yamaha grease D) on the propeller shaft¹³
Exhaust	Exhaust guide and exhaust manifold: check every 1000 h¹³

Hours or months, whichever comes first, from Yamaha Europe’s owner’s manual 6AG-28199-7K-E0 (2026 edition; the 2012 edition 6AG-28199-77-E0 has the same chart), which assumes about 100 h of use a year. For long trolling, frequent full-throttle running, frequent starts and shifts or changing loads, Yamaha halves every interval. The Japanese owner’s manual differs in places: first service at 10 h or 1 month, engine oil every 100 h or 6 months, oil filter after 10 h and then every 200 h or yearly, impeller check or replacement every 100 h or 6 months (2026 edition) and valve clearance every 200 h or yearly.

Specifications

Type	Four-stroke, SOHC with toothed-belt drive; one carburettor with Yamaha Prime Start^13,33
Cylinders	2 in line, 4 valves (2 per cylinder)¹³
Displacement	362 cc (22.1 cu in)¹³
Bore × stroke	63.0 × 58.1 mm¹³
Compression ratio	9.3:1³³
Power	F15C: 11.0 kW (15 hp), F20B: 14.7 kW (20 hp), both at 5500 rpm; F9.9H (Europe): 7.3 kW (9.9 hp)^34,13
Full-throttle range	5000–6000 rpm¹³
Idle speed	1000–1100 rpm in neutral; European EHP (tiller, power tilt) and Japanese versions 1150–1250 rpm³³
Ignition	CDI; timing TDC to 30° BTDC³³
Cooling	Raw water with thermostat; rubber impeller in a stainless-steel pump housing in the gearcase; garden-hose flushing connector on the bottom cowling³³
Engine oil capacity	1.8 l with filter change, 1.6 l without¹³
Engine oil grade	Yamalube 4 or another four-stroke outboard oil, SAE 10W-30, 10W-40 or 5W-30, API SE, SF, SG, SH, SJ or SL¹³
Gearbox	Forward, neutral, reverse; 2.08:1 (27/13)¹³
Gear oil capacity	0.250 l (250 ml)¹³
Gear oil grade	Yamalube outboard gear oil or hypoid gear oil SAE 90, API GL-4¹³
Spark plug	NGK DPR6EB-9, 2 per engine¹³
Spark plug gap	0.8–0.9 mm¹³
Valve clearance (cold)	Intake 0.15–0.25 mm, exhaust 0.25–0.35 mm¹³
Tightening torques	Spark plug 17 N·m, oil drain screw 19.5 N·m, oil filter 18 N·m, propeller nut 17 N·m¹³
Alternator	Up to 10 A on every version except the pull-start-only MH, which needs the optional rectifier/regulator to charge a battery³³
Fuel	Unleaded petrol, at least 90 RON; Yamaha US: 87 octane, max. 10 % ethanol, plus an external 10-micron fuel/water separating filter^13,35
Fuel consumption	About 5.3 l/h (F15C) and 6.9 l/h (F20B) at 5500 rpm³³
Propeller	3-blade aluminium, 9¼ in diameter, splined shaft; Yamaha series J/J1 (the F20B uses J1)¹³
Shaft length	S 15 in (transom height 438 mm), L 20 in (565 mm); power-tilt versions 443 mm (S) and 570 mm (L)¹³
Dry weight	With aluminium propeller: 51 kg (15 in, tiller, pull start) to 61 kg (20 in, power tilt); Yamaha US gives 50–59 kg (111–132 lb) for its F15^13,35
Versions	MH = tiller, pull start; WH = tiller, pull and electric start; EH = tiller, electric start; EHP = tiller, electric start, power tilt; E = remote control; EP = remote control, power tilt; S or L at the end = 15 or 20 in shaft, e.g. F15CMHS, F15CEHL, F20BEPS¹³
Models	Model codes 6AG (F15C) and 6AH (F20B), approval codes 6AGK / 6AHK; owner’s manual number 6AG-28199. The same engine: the European F9.9H, the 2026 European F15MHA, F15EHA, F15PHA, F15EA, F15PA and F20PA, and the US carburettor F15 and F20 (e.g. 2008 F20MSH, 2012 F15SMHA, 2014 F20SMHA). The current US F20 with EFI is the 432 cc engine, so check the engine label^{33,13,15,9,4,36}
Years built	Since 2006 (announced on 7 September 2006); still in production in 2026^34,13,37

Good to know

Before buying filters or a pump kit, read the engine label: F15C (model code 6AG) and F20B (6AH) are the 362 cc carburettor engine. The fuel-injected F20G is a 432 cc engine with less oil (1.0/1.1 l), more gear oil (0.37 l) and a 16 A alternator, so its parts are different; check the label on fuel-injected US F20s too.^36,33
Change the oil with the engine warm and upright. It takes 1.8 l with a new filter and 1.6 l without; fit a new gasket on the drain screw (19.5 N·m) and tighten the spin-on filter by hand to about 18 N·m.¹³
The gearcase holds only 250 ml. Drain it from the bottom screw, refill from the bottom until oil runs out of the level hole, and fit new gaskets on both screws. Milky or watery oil means a leaking seal, so have it checked before the next season.¹³
Check the cooling-water tell-tale every time you start. If the overheat warning drops the revs to about 2000–3500 rpm, stop and make sure the water intake on the gearcase is submerged and clear; if the oil-pressure warning comes on, check the dipstick. A weak stream usually means a worn impeller, so a pump kit is a good spare to carry.¹³
After use in salt water, flush through the garden-hose connector on the bottom cowling for about 15 minutes with the engine off. Then screw the connector back on firmly: if it is left loose, cooling water escapes there and the engine can overheat.¹³
Before winter lay-up, fog the carburettor while the engine runs on flushing water, or let it run until the carburettor is empty. Petrol left in the float bowl gums up the small jets.¹³

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Sources

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