Yamaha F2 5 Service Manual

							69M3E111-16
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Checking the engine oil
1. Check the oil level through the oil level
window 1
.
NOTE:
If the engine oil is above the maximum level
a
, drain sufficient oil until the level is
between a
 and b
.
If the engine oil is below the minimum level
b
, add sufficient oil until the level is
between a
 and b
.
Checking the outboard motor 
mounting height
1. Check that the anti-cavitation plate is
between the bottom of the boat and a
maximum of 25 mm (1 in) a
 below it. If
the mounting height is too high, cavita-
tion will occur and propulsion will be
reduced. Also, the engine speed will
increase abnormally and cause the
engine to overheat. If the mounting
height is too low, water resistance will
increase and reduce engine efficiency.
NOTE:
The optimum mounting height is affected by
the combination of the boat and the outboard
motor. To determine the optimum mounting
height, test run the outboard motor at differ-
ent heights.
2. Check that the clamp brackets are
secured with the clamp screws.
Checking the steering system
1. Check the steering friction for proper
adjustment.
Recommended engine oil:
4-stroke motor oil
API: SE, SF, SG, SH, or SJ
SAE: 10W-30 or 10W-40
Oil quantity:
0.35 L (0.09 US gal, 0.08 Imp gal)
S69M3040
aa
bb
Propeller selection / Predelivery checks 
						

							GEN 
INFO
General information
1-1769M3E11
2. Check that the steering operates
smoothly.
Checking the gear shift and throttle 
operation
1. Check that the gear shift operates
smoothly when the shift lever is shifted
from neutral into forward.
2. Check that the throttle operates smoothly
when the throttle grip is turned from the
fully closed position to the fully open
position a
.
Checking the engine shut-off switch
1. Check that the engine turns off when the
engine stop switch is pushed or the
engine shut-off cord is pulled from the
engine shut-off switch.
Checking the cooling water pilot 
hole
1. Check that cooling water is discharged
from the cooling water pilot hole. 
						

							69M3E111-18
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Test run
1. Start the engine, and then check that the
gear shift operates smoothly.
2. Check the engine idle speed after the
engine has been warmed up.
3. Operate at trolling speed.
4. Run the outboard motor for one hour at
2,000 r/min or at half throttle, then for
another hour at 3,000 r/min or at 3/4
throttle.
NOTE:
The test run is part of the break-in operation.
Break-in
During the test run, perform the break-in
operation in the following three stages. 
1. One hour a
 at 2,000 r/min or at approxi-
mately half throttle
2. One hour b
 at 3,000 r/min or 3/4 throttle
and one minute out of every ten at full
throttle
3. Eight hours c
 at any speed, however,
avoid running at full speed for more than
five minutes
È
Hour
After test run
1. Check for water in the gear oil.
2. Check for fuel leakage in the cowling.
3. After a test run and while the engine is at
idle, flush the cooling water passage with
fresh water using the flushing kit.
Adjusting the engine idle speed
Adjust the idle speed after completing the
break-in period.
With the smallest engine and lowest output,
the idle speed tends to rise by the reduction
of the engine internal friction due to the
break-in.
1. Warm the engine up for 5 minutes, and
then turn it off.
2. Attach the special service tool to the
spark plug wire 1
.
3. Start the engine, and then check the
engine idle speed. Adjust if out of specifi-
cation.
S69J1240
0
1210
Digital tachometer: 90890-06760
Engine idle speed:
1,800–2,000 r/min
Predelivery checks 
						

							GEN 
INFO
General information
1-1969M3E11
4. Turn the throttle stop screw 2
 in direc-
tion a
 or b
 until the specified idle speed
is obtained.
NOTE:
To increase the idle speed, turn the throttle
stop screw in direction a
.
To decrease the idle speed, turn the throttle
stop screw in direction b
.
5. After adjusting the idle speed, rev the
engine a few times and let it idle for at
least 15 seconds to check the stability of
the engine. If necessary, repeat steps 3–
5. 
						

							69M3E11
SPEC
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Specifications
General specifications ................................................................................... 2-1
Maintenance specifications .......................................................................... 2-3
Power unit.................................................................................................. 2-3
Electrical .................................................................................................... 2-5
Dimensions ................................................................................................ 2-6
Tightening torques......................................................................................... 2-8
Specified torques ....................................................................................... 2-8
General torques ......................................................................................... 2-9 
						

							SPECSpecifications
2-169M3E11
General specifications2
Item UnitModel
F2.5AMH
Dimension
Overall length mm (in) 623 (24.5)
Overall width mm (in) 345 (13.6)
Overall height
(S) mm (in) 1,021 (40.2)
(L) mm (in) 1,148 (45.2)
Boat transom height
(S) mm (in) 381 (15.0)
(L) mm (in) 508 (20.0)
Weight*
(S) kg (lb) 17.0 (37.5)
(L) kg (lb) 17.5 (38.6)
Performance
Maximum output kW (hp) 
at 5,500 r/min1.8 (2.5)
Full throttle operating range r/min 5,250–5,750
Maximum fuel consumption L (US gal, 
lmp gal)/hr 
at 5,500 r/min1.1 (0.29, 0.24)
Power unit
Type 4-stroke, single cylinder, OHV
Cylinder quantity 1
Displacement cm
3 (cu. in) 72 (4.4)
Bore ×
 stroke mm (in) 54.0 ×
 31.5 (2.13 ×
 1.24)
Compression ratio 9.0
Control system Tiller control
Starting system Manual starter
Enrichment system Choke valve
Ignition control system TCI
Ignition timing Degree BTDC 30
Spark plug BR6HS (NGK)
Cooling system Water
Exhaust system Under water
Lubrication system Splash
* Includes an aluminum propeller and excludes oil and fuel. 
						

							69M3E112-2
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Fuel and oil
Fuel type Regular unleaded gasoline
Fuel rating PON*
RON86
91
Fuel tank capacity L (US gal, 
lmp gal)0.9 (0.24, 0.20)
Engine oil type 4-stroke motor oil
Engine oil grade API
SAESE, SF, SG, SH, or SJ
10W-30 or 10W-40
Engine oil quantity L (US gal, 
lmp gal)0.35 (0.09, 0.08)
Gear oil type Hypoid gear oil
Gear oil grade SAE 90
Gear oil quantity cm
3 (US oz, 
lmp oz)75 (2.5, 2.6)
Bracket
Trim angle 
(at 12 degree boat transom)Degree 0, 4, 8, 12
Tilt-up angle  Degree 80
Steering angle Degree 360
Drive unit
Gear shift positions F-N
Gear ratio 2.08 (27/13)
Reduction gear type Straight bevel gear
Clutch type Dog clutch
Propeller shaft type Spline
Propeller direction
(rear view)Clockwise
Propeller identification mark BS
* PON: Pump Octane Number (Research Octane Number + Motor Octane Number)/2
RON: Research Octane NumberItem UnitModel
F2.5AMH
General specifications 
						

							SPECSpecifications
2-369M3E11
Maintenance specifications2
Power unit
Item UnitModel
F2.5AMH
Power unit
Minimum compression 
pressure*kPa 
(kgf/cm
2, psi)700 (7.0, 102)
Cylinder head
Warpage limit mm (in) 0.1 (0.004)
(lines indicate straightedge 
position)
Cylinder
Bore size mm (in) 54.000–54.015 (2.1260–2.1266)
Taper limit mm (in) 0.08 (0.0031)
Out-of-round limit mm (in) 0.05 (0.0020)
Piston
Piston diameter (D) mm (in) 53.950–53.965 (2.1240–2.1246)
Measuring point (H) mm (in) 0 (0)
Piston-to-cylinder clearance  mm (in) 0.035–0.065 (0.0014–0.0026)
Piston pin boss bore mm (in) 12.009–12.017 (0.4728–0.4731)
Piston pin
Outside diameter mm (in) 11.996–12.000 (0.4723–0.4724)
Piston rings
Top ring
Dimension B mm (in) 0.97–0.99 (0.0382–0.0390)
Dimension T mm (in) 1.95–2.15 (0.0768–0.0846)
End gap mm (in) 0.15–0.30 (0.0059–0.0118)
Side clearance mm (in) 0.04–0.08 (0.0016–0.0031)
2nd ring
Dimension B mm (in) 1.17–1.19 (0.0461–0.0468)
Dimension T mm (in) 2.30–2.50 (0.0906–0.0984)
End gap mm (in) 0.30–0.45 (0.0118–0.0177)
Side clearance mm (in) 0.02–0.06 (0.0008–0.0024)
* Measuring conditions:
Ambient temperature 20 °C (68 °F), wide open throttle, with spark plug removed from cylinder.
The figures are for reference only. 
						

							69M3E112-4
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Oil ring
Dimension B mm (in) 1.87–1.95 (0.0736–0.0768)
Dimension T mm (in) 2.10–2.40 (0.0827–0.0945)
End gap mm (in) 0.20–0.70 (0.0079–0.0276)
Side clearance mm (in) 0.06–0.16 (0.0024–0.0063)
Camshaft
Intake and 
exhaust (A)mm (in) 26.139–26.239 (1.0290–1.0330)
Intake and 
exhaust (B)mm (in) 21.950–22.050 (0.8642–0.8681)
Camshaft journal diameter mm (in) 14.965–14.990 (0.5892–0.5902)
Camshaft journal oil clearance mm (in) 0.010–0.053 (0.0004–0.0021)
Camshaft runout limit mm (in) 0.03 (0.0012)
Valves
Valve clearance (cold)
Intake and exhaust mm (in) 0.08–0.12 (0.0031–0.0047)
Head diameter (A)
Intake mm (in) 23.9–24.1 (0.941–0.949)
Exhaust mm (in) 21.9–22.1 (0.862–0.870)
Face width (B)
Intake and exhaust mm (in) 1.84–2.26 (0.0724–0.0890)
Seat contact width (C)
Intake and exhaust mm (in) 0.6–0.8 (0.024–0.031)
Margin thickness (D)
Intake mm (in) 0.7 (0.028)
Exhaust mm (in) 1.0 (0.040)
Stem diameter
Intake mm (in) 5.475–5.490 (0.2156–0.2161)
Exhaust mm (in) 5.460–5.475 (0.2150–0.2156)
Guide inside diameter
Intake and exhaust mm (in) 5.500–5.512 (0.2165–0.2170)
Stem-to-guide clearance
Intake mm (in) 0.010–0.037 (0.0004–0.0015)
Exhaust mm (in) 0.025–0.052 (0.0010–0.0020)
Stem runout limit mm (in) 0.03 (0.0012)
Valve springs
Free length mm (in) 35.0 (1.378)
Tilt limit mm (in) 1.2 (0.05)Item UnitModel
F2.5AMH
Maintenance specifications 
						

							SPECSpecifications
2-569M3E11
Electrical
Connecting rod
Small end inside diameter mm (in) 12.006–12.020 (0.4727–0.4732)
Big end inside diameter mm (in) 24.000–24.015 (0.9449–0.9455)
Big end side clearance mm (in) 0.2–0.6 (0.008–0.024)
Crankpin oil clearance mm (in) 0.016–0.046 (0.0006–0.0018)
Crankshaft
Crankshaft journal diameter mm (in) 21.980–21.993 (0.8654–0.8659)
Crankpin diameter mm (in) 23.969–23.984 (0.9437–0.9443)
Crankpin width mm (in) 21.0–21.1 (0.827–0.831)
Runout limit mm (in) 0.01 (0.0004)
Thermostat
Opening temperature°C (°F) 48–52 (118–126)
Fully open temperature°C (°F) 60 (140)
Valve open lower limit mm (in) 3 (0.12)
Carburetor
ID mark 69M00
69M20
Main jet # 62
Pilot jet # 37
Pilot screw Turns out 2–3
Float height mm (in) 10.5–11.5 (0.413–0.453)
Engine speed
Engine idle speed r/min 1,800–2,000
Item UnitModel
F2.5AMH
Ignition system
Ignition timing Degree BTDC 30
Ignition spark gap mm (in) 7 (0.28)
Spark plug cap resistance kΩ
 4.0–6.0
TCI unit air gap mm (in) 0.4–0.6 (0.016–0.024)
TCI unit resistance
Primary coil (W – B)Ω
 0.56–0.84
Secondary coil
(W – spark plug wire)kΩ
 11.6–17.4 Item UnitModel
F2.5AMH