Yamaha F50 Service Manual

62Y3A118-20
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Checking the fuse
1. Check the fuse and fuse holder for conti-
nuity. Replace if there is no continuity.
Checking the wiring harness 
(10 pins)
1. Check the wiring harness for continuity.
Replace if there is no continuity.
Checking the neutral switch
1. Check the neutral switch for continuity.
Replace if there is no continuity.
Checking the starter relay
1. Connect the digital circuit tester leads to
the starter relay terminals.
2. Connect the brown (Br) lead to the posi-...

ELECElectrical systems
–+
8-2162Y3A11
Starter motor8 

62Y3A118-22
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No. Part name Q’ty RemarksTightening torques
Stage N·mkgf·mft·lb
1 Clip 1
2 Pinion stopper 1
3Spring 1
4 Starter motor pinion 1
5 Upper bracket 1
6 O-ring 1
Not reusable
7 Washer 1 1
8Shim—As required
9 Washer 2 1
10 Armature 1
11 Stator 1
12 O-ring 1
Not reusable
13 Brush holder assembly 1
14 Brush set 1
15 O-ring 1
Not reusable
16 Washer 1
17 Spring washer 1
18 Nut 1 9 0.9 6.5
19 Lower bracket 1
20 Screw 2 M4 ×
 12 mm
21 Bolt 2 M5 ×
 125 mm
Starter motor 

ELECElectrical systems
–+
8-2362Y3A11
Removing the starter motor pinion
1. Slide the pinion stopper 1
 down as
shown, and then remove the clip 2
.
Checking the starter motor pinion
1. Check the pinion teeth for cracks or
wear. Replace if necessary.
2. Check for smooth operation. Replace if
necessary.
NOTE:
Turn the pinion clockwise to check that it
operates smoothly and turn it counterclock-
wise to check that it locks.
Checking the armature
1. Check the armature axial free play.
Replace the washers and...

62Y3A118-24
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4. Measure the commutator undercut a
.
Replace the armature if out of specifica-
tion.
5. Check the armature for continuity.
Replace if out of specifications.
Checking the brushes
1. Measure the brush length. Replace the
brush assembly if out of specification.2. Check the brush holder for continuity.
Replace if out of specifications.
Checking the starter motor operation
1. Check the operation of the starter motor
after installing it to the power unit. Commutator undercut...

ELECElectrical systems
–+
8-2562Y3A11
Charging system8
1Lighting coil
2Rectifier Regulator
3Fuse
4BatteryB: Black
G: Green
R: Red
G/W : Green/white 

62Y3A118-26
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Checking the lighting coil
1. Measure the lighting coil output peak
voltage. Replace the stator coil if below
specification.
 WARNING
When checking the peak voltage do not
touch any of the connections of the digital
tester leads.
NOTE:
Use the peak voltage adaptor with the digi-
tal circuit tester.
When measuring the peak voltage, set the
selector on the digital circuit tester to the
DC voltage mode
.
Checking the Rectifier Regulator
1. Measure the Rectifier Regulator...

ELECElectrical systems
–+
8-2762Y3A11
NOTE:
After starting the engine, disconnect the out-
put lead (red lead) of the Rectifier Regulator
when measuring the output peak voltage.Rectifier Regulator output peak voltage:
Red (R) – Black (B)
r/minUnloaded
1,500 3,500
DC V 18.9 19.5 

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— MEMO — 

Index
i-162Y3A11
A.
Acceleration pump .................................... 1-15
Adjusting the dash-pot 
(acceleration pump) ................................ 4-24
Adjusting the pilot screw ........................... 4-22
Adjusting the throttle link rod..................... 4-21
Adjusting the trim sensor .......................... 7-46
After test run ............................................. 1-36
Applicable models ....................................... 1-5
Assembling the carburetor...