Yamaha F2 5 Service Manual

							69M3E118-4
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Ignition system8
Checking the ignition spark gap
1. Disconnect the spark plug cap 1
 from
the spark plug.
2. Connect the special service tool to the
spark plug cap and to the ground bolt.
3. Set the spark gap length on the adjusting
knob.
4. Crank the engine and observe the spark
through the discharge window of the
spark gap tester. Check the TCI unit or
spark plug cap if out of specification.
 WARNING
•Do not touch any of the connections of
the spark gap tester leads.
•Keep flammable gas or liquids away,
since this test can produce sparks.
Checking the spark plug cap
1. Remove the spark plug cap from the
spark plug wire by turning the cap coun-
terclockwise.
2. Measure the spark plug cap resistance.
Replace if out of specification.Ignition tester: 90890-06754
Ignition spark gap: 7 mm (0.28 in)
S69M8040
1
Spark plug cap resistance:
4.0–6.0 kΩ
 
OK
S69M8060
Ω × 1K
S69M8080
Electrical components / Ignition system 
						

							ELECElectrical systems
–+
8-569M3E11
Checking the TCI unit
1. Remove the spark plug cap from the
spark plug wire by turning the cap coun-
terclockwise.
2. Measure the TCI unit resistance.
Replace if out of specification.
Checking the engine shut-off switch
1. Check the engine shut-off switch for con-
tinuity. Replace if there is no continuity.
TCI unit resistance:
Primary coil:
White (W) – Black (B)
0.56–0.84 Ω
 
Secondary coil:
White (W) – Spark plug wire
11.6–17.4 kΩ
 
Lead color
White (W) Black (B)
Clip removed a
Clip installed b
Engine stop button 
pushed c 
						

							69M3E11
TRBL
SHTG
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Troubleshooting
Power unit ....................................................................................................... 9-1 
						

							TRBL
SHTG
Troubleshooting
9-169M3E11
NOTE:
To diagnose a mechanical malfunction, use the troubleshooting charts pertaining to the trouble
located in this chapter. Also, when checking and maintaining the outboard motor, see Chapters 4–
8 for safe maintenance procedures.
Check that all electrical connections are tight and free from corrosion.
Power unit9
Symptom: Engine does not start (manual starter is operating normally).
Check the ignition system.
Check the fuel system.
Check the compression pressure of the power unit.
Check the engine shut-off switch 
for continuity (with clip installed).
Replace the engine shut-off 
switch.Is there 
continuity?No
Check the ignition spark gap 
using the spark gap tester.
Continued on next page. WARNING
•Do not touch any of the connections of the
spark gap tester leads.
•Keep flammable gas or liquids away, since
this test can produce sparks.
No
Yes
Check the condition of the spark 
plug.
Check the TCI unit or spark plug 
cap.Out of specifica-
tion?
Yes 
						

							69M3E119-2
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NoClean, adjust or replace the 
spark plug.Good condition?
Check the compression pres-
sure of the combustion chamber.
Out of 
specification?
Yes
NoCheck the fuel system.
Out of 
specification?
No
Check the cylinder head, cylin-
der body, and piston assembly.
Check the valve clearance.
YesAdjust the valve clearance.
Power unit 
						

							TRBL
SHTG
Troubleshooting
9-369M3E11
Symptom: Engine can be started, but does not remain on.
Check the fuel system.
Check the ignition system.
Check the compression pressure of the power unit.
Fuel system
Ignition system
Is the vent 
screw open?
Residue?
Kinks or fuel 
leakage?
Check for residue in the fuel 
filter.
Open the air vent screw.
Check the fuel hose for kinks or 
fuel leakage.
No
Yes
Yes
No
Check that the air vent screw of the fuel tank is open.
YesReplace the 
respective parts.
Check the carburetor.
No
Clean the fuel tank.
Out of 
specification?
Yes
No
Check the ignition spark gap using the spark gap tester.
Check the spark plug.
Check the TCI unit or spark plug 
cap. 
						

							69M3E119-4
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Compression pressure
Symptom: The engine idle speed is not steady, but increases or decreases.
Check the intake manifold.
Check the air intake system.
Check the ignition system.
Is there air 
intake?Replace the respective seals.
Check the compression pres-
sure of the combustion chamber.
No
Yes
Check that there is no secondary air intake on the contact surfaces of 
the carburetor.
Out of 
specification?
Check the ignition timing.
Yes
No
Check the operation of the 
throttle cable and throttle link.
Yes
NoAdjust the throttle cable and 
throttle link.Good operat-
ing condition?
Check the TCI unit air gap.
Check the secondary air intake 
on the O-ring and the gaskets.Power unit 
						

							TRBL
SHTG
Troubleshooting
9-569M3E11
Symptom: Engine does not accelerate when the throttle is opened quickly.
The engine turns off when the throttle is opened quickly.
Acceleration is tardy and the engine is likely to stop at any moment.
Check the carburetors.
Check the ignition system.
Check the compression pressure of the power unit.
Check the throttle cable 
operation.
Do the car-
buretor throt-
tle valves 
close simul-
taneously?
Yes
Yes
No
Disassemble the carburetor and 
check the internal parts for 
clogs, debris, or wear.
Clean the carburetor or replace 
the respective parts.
Adjust the throttle cable.
Clogs, debris, 
or wear?Check the ignition system and 
the compression pressure of the 
power unit.
No 
						

							69M3E119-6
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Symptom: Shift mechanism of the forward gear does not operate properly.
Check the operation of the shift 
lever.
Replace the shift rod.
Check the bracket, spring, and 
ball.Good operat-
ing condition?
Connected 
properly?
Yes
Yes
No
No
Disassemble the lower case, 
and then check the operation of 
the dog clutch.
Yes
NoReplace the respective parts.Good operat-
ing condition?
Check the condition of the shift 
rod connection.
Check the forward gear.Power unit 
						

							Index
i-169M3E11
A.
Adjusting the engine idle speed ................ 1-18
Adjusting the pilot screw ........................... 4-10
After test run ............................................. 1-18
Applicable model......................................... 1-5
Assembling the carburetor .......................... 4-9
Assembling the clamp brackets .................. 7-9
Assembling the crankcase ........................ 5-32
Assembling the cylinder block................... 5-31
Assembling the lower case ....................... 6-12
Assembling the manual starter ................... 5-8
Assembling the piston and 
cylinder block .......................................... 5-33
Assembling the propeller shaft 
assembly ................................................... 6-9
Assembling the propeller shaft housing ...... 6-9
Assembling the swivel bracket .................... 7-8
Assembling the tiller handle ........................ 7-3
Automatic tilt support and steering pivot 
immobilization system ............................. 1-13
B.
Blowby gas reburning system ..................... 1-7
Break-in..................................................... 1-18
C.
Carburetor ................................................... 4-5
Carburetor and intake silencer .................... 4-4
Changing the engine oil .............................. 3-4
Changing the gear oil ................................ 3-10
Checking the anodes ................................ 3-11
Checking the camshaft ............................. 5-29
Checking the carburetor.............................. 4-7
Checking the compression pressure........... 5-7
Checking the connecting rod big end 
side clearance ......................................... 5-27
Checking the connecting rod small end 
inside diameter........................................ 5-27
Checking the cooling water passage .......... 3-7
Checking the cooling water pilot hole ....... 1-17
Checking the crankpin oil clearance ......... 5-28
Checking the crankshaft ........................... 5-27
Checking the cylinder bore ....................... 5-25
Checking the cylinder head....................... 5-20
Checking the drive shaft ........................... 6-12
Checking the engine idle speed .................. 3-7
Checking the engine oil..................... 1-16
, 3-3
Checking the engine shut-off 
switch .............................................. 1-17
, 8-5
Checking the fuel cock ................................ 4-7
Checking the fuel filter ........................ 3-3
, 4-7
Checking the fuel line.................................. 3-3Checking the fuel system ......................... 1-15
Checking the fuel tank and 
fuel filler cap ............................................. 4-7
Checking the gear oil ................................ 1-15
Checking the gear oil level ......................... 3-9
Checking the gear shift and 
throttle operation..................................... 1-17
Checking the ignition spark gap ................. 8-4
Checking the ignition timing........................ 3-8
Checking the lower case .......................... 6-12
Checking the lower unit for air leakage .... 3-11
Checking the oil seal housing ................... 5-32
Checking the oil splasher gear ................. 5-30
Checking the outboard motor 
mounting height ...................................... 1-16
Checking the pinion and forward gear ...... 6-12
Checking the piston clearance ................. 5-25
Checking the piston diameter ................... 5-24
Checking the piston pin ............................ 5-27
Checking the piston pin boss bore ........... 5-26
Checking the piston ring grooves ............. 5-26
Checking the piston ring side clearance ... 5-26
Checking the piston rings ......................... 5-25
Checking the propeller.............................. 3-11
Checking the propeller shaft ....................... 6-9
Checking the propeller shaft housing ......... 6-8
Checking the push rod guide .................... 5-15
Checking the push rods ............................ 5-15
Checking the rocker arms......................... 5-15
Checking the spark plug ............................. 3-5
Checking the spark plug cap ...................... 8-4
Checking the spiral spring .......................... 5-8
Checking the steering system .................. 1-16
Checking the TCI unit ................................. 8-5
Checking the TCI unit air gap ..................... 3-9
Checking the thermostat............................. 3-6
Checking the valve clearance..................... 3-4
Checking the valve guides........................ 5-16
Checking the valve lifters.......................... 5-30
Checking the valve seat ........................... 5-18
Checking the valve springs....................... 5-15
Checking the valves ................................. 5-16
Checking the water pump and shift rod ...... 6-6
Control system............................................ 3-7
Cooling water flow chart ........................... 1-14
Cylinder block ........................................... 5-22
Cylinder head ........................................... 5-12