Yamaha YFM45FAR, YFM450FAR. Service Manual

4 - 82

ENG

MIDDLE GEAR

4.Check:

●

O-ring
Damage

→

Replace.

●

Bearings
Pitting/damage

→

Replace.

5.Check:

●

U-joint movement
Roughness

→

Replace U-joint.

SELECTING THE MIDDLE DRIVE AND
DRIVEN GEAR SHIM

When the drive and driven gear, bearing
housing assembly and/or crankcase replaced,
be sure to adjust the gear shim

1.Select:

●

Middle drive gear shim

●

Middle driven gear shim

*****************************************************

Selection steps:

●

Position middle drive and driven gear by
using shims

and

with their respective

thickness calculated from information
marked on crankcase, bearing housing and
drive gear end.

Shim thickness “A”

Shim thickness “B”

●

To find shim thickness “A” use following
formula:

Where:

= a numeral (usually a decimal number)

on the bearing housing is either added
to or subtracted from “10.5”.

= drive pinion gear to driven pinion gear

center distance (considered constant
“55”).

= a numeral (usually a decimal number)

on the right crankcase specifies a
thickness of “66”.

Middle drive pinion gear shim thickness:

“A” =

–

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MIDDLE GEAR

Example:

1) If the bearing housing is marked “+04”,

......

is 10.54.

is 55

3) If the crankcase (right) is marked “66.03”,

......

is 66.03.

4) Therefore, the shim thickness is 0.47 mm.

A = 66.03 – 10.54 – 55

= 0.49

5) Round off hundredths digit and select

appropriate shim(s).
In the example above, the calculated shim
thickness is 0.49 mm. The chart instructs
you, however, to round off 9 to 10.

Shims are supplied in the following thickness.

Hundredths

Round value

0, 1, 2

3, 4, 5, 6, 7

8, 9

Middle drive pinion gear shim

Thickness (mm)

0.10

0.30

0.15

0.40

0.20

0.50

●

To find shim thickness “B” use the following
formula:

Middle driven pinion gear shim
thickness:

“B” =

–

– 0.05

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MIDDLE GEAR

Where:

= a numeral (usually a decimal number)

on the bearing housing is either added
to or subtracted from “76”.

= a numeral (usually a decimal number)

on the middle driven pinion gear is
either added to or subtracted from “59”.

= a numeral (usually a decimal number)

on the middle driven pinion gear is
either added to or subtracted from
“79.5”.

= a numeral (usually a decimal number)

on the left crankcase specifies a
thickness of “95.8”.

Example:

1) If the bearing housing is marked “+03”,

......

is 76.03.

2) If the driven pinion gear is marked “+02”,

......

is 59.02.

3) If the driven pinion gear is marked “–10”,

......

is 79.40.

4) If the crankcase (left) is marked “95.79”,

......

is 95.79.

5) Therefore, the shim thickness is 0.57 mm.

B = 76.03 – 59.02 + 79.40 – 95.79 – 0.05

= 0.57

6) Round off hundredths digit and select

appropriate shim(s).
In the example above, the calculated shim
thickness is 0.57 mm. The chart instructs
you, however, to round off 7 to 5.

Hundredths

Round value

0, 1, 2

3, 4, 5, 6, 7

8, 9

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ENG

MIDDLE GEAR

Shims are supplied in the following thickness.

*****************************************************

Middle drive pinion gear shim

Thickness (mm)

0.10

0.40

0.15

0.50

0.20

0.60

0.30

INSTALLING THE MIDDLE DRIVEN SHAFT

1.Install:

●

Bearing retainer

NOTE:

Attach the ring nut wrench

CAUTION:

The middle driven shaft bearing retainer
has left-handed threads. To tighten the
retainer turn it counterclockwise.

2.Install:

●

Bearing retainer

*****************************************************

Installation steps:

●

Attach the folded rag

●

Secure the bearing housing edge in the vise.

●

Attach the bearing retainer wrench

Ring nut wrench:

P/N. YM-38404, 90890-01430

Bearing retainer wrench:

P/N. YM-04128, 90890-04128

80 Nm (8.0 m • kg, 58 ft • lb)

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MIDDLE GEAR

●

Tighten the bearing retainer.

CAUTION:

The middle driven shaft bearing retainer
has left-handed threads. To tighten the
retainer turn it counterclockwise.

*****************************************************
3.Install:

●

Shims

●

Bearing housing

NOTE:

Install the shims so that the tabs are positioned
as shown in the illustration.

Bearing retainer:

110 Nm (11.0 m • kg, 80 ft • lb)

4.Install:

●

Universal joint yoke (rear side)

●

Washer

●

Nut

NOTE:

Use the universal joint holder

to hold the

yoke.

Universal joint holder:

P/N. YM-04062, 90890-04062

97 Nm (9.7 m • kg, 70 ft • lb)

5.Install:

●

Universal joint

*****************************************************

Installation steps:

●

Install the opposite yoke into the U-joint.

●

Apply wheel bearing grease to the bearings.

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MIDDLE GEAR

●

Install the bearing

onto the yoke.

CAUTION:

Check each bearing. The needles can
easily fall out of their races. Slide the yoke
back and forth on the bearings; the yoke
will not go all the way onto a bearing if a
needle is out of place.

●

Press each bearing into the U-joint using a
suitable socket.

NOTE:

The bearing must be inserted far enough into
the U-joint so that the circlip can be installed.

●

Install the circlips

into the groove of each

bearing.

*****************************************************

INSTALLING THE MIDDLE DRIVE SHAFT

1.Tighten:

●

Nut (middle drive pinion gear)

NOTE:

Secure the middle drive shaft in the vise with a
clean rag.

2.Lock the threads with a drift punch.

New

130 Nm (13.0 m • kg, 94 ft • lb)

MEASURING THE MIDDLE GEAR
BACKLASH

1.Measure:

●

Gear lash

*****************************************************

Measurement steps:

●

Temporarily install the right crankcase.

●

Wrap a rag

around a screwdriver

, and

then insert it into the installation hole

the left crankcase speed sensor to hold the
middle driven gear.

Middle gear lash:

0.1 ~ 0.3 mm (0.004 ~ 0.012 in)

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MIDDLE GEAR

●

Attach the gear lash measurement tool

and dial gauge

8.12 mm (0.32 in)

●

Measure the gear lash while rotating the
middle driven shaft back and forth.

NOTE:

Measure the gear lash at 4 positions. Rotate
the middle driven gear 90° each time.

●

If the gear lash is incorrect, adjust the gear
lash by middle driven pinion gear shims and/
or middle drive pinion gear shim(s).

*****************************************************

Gear lash measurement tool:

P/N. YM-01467, 90890-01467

COOL

CHAPTER 5.

COOLING SYSTEM

RADIATOR

................................................................................................... 5-1

CHECKING THE RADIATOR ................................................................ 5-3
INSTALLING THE RADIATOR .............................................................. 5-4

THERMOSTAT

............................................................................................. 5-5

CHECKING THE THERMOSTAT ......................................................... 5-6
INSTALLING THE THERMOSTAT ....................................................... 5-6

WATER PUMP

.............................................................................................. 5-7

DISASSEMBLING THE WATER PUMP ............................................... 5-9
CHECKING THE WATER PUMP .......................................................... 5-9
ASSEMBLING THE WATER PUMP ................................................... 5-10

5 - 1

COOL

RADIATOR

COOLING SYSTEM

RADIATOR

Order

Job name/Part name

Q’ty

Remarks

Removing the radiator

Remove the parts in the order below.

Seat and fuel tank side panels

Refer to “SEAT AND SIDE PANELS” in
CHAPTER 3.

Front carrier, front bumper and front
fender

Refer to “FRONT CARRIER, FRONT
BUMPER AND FRONT FENDER” in
CHAPTER 3.

Left footrest board

Refer to “FOOTREST BOARDS” in
CHAPTER 3.

Coolant

Drain.
Refer to “CHANGING THE COOLANT” in
CHAPTER 3.

Radiator fan coupler

Disconnect.

Thermo switch coupler

Disconnect.

Coolant reservoir hose

Disconnect.

Radiator fan breather hose

5 - 2

COOL

RADIATOR

Order

Job name/Part name

Q’ty

Remarks

Radiator inlet hose

Disconnect.

Radiator outlet hose

Disconnect.

Radiator

Radiator fan

Thermo switch

For installation, reverse the removal
procedure.

5 - 3

COOL

RADIATOR

CHECKING THE RADIATOR

1.Check:

●

Radiator fins
Obstruction

→

Clean.

Apply compressed air to the rear of the
radiator.
Damage

→

Repair or replace.

NOTE:

Straighten any flattened fins with a thin, flat-
head screwdriver.

2.Check:

●

Radiator hoses
Cracks/damage

→

Replace.

3.Measure:

●

Radiator cap opening pressure
Below the specified pressure

→

Replace the

radiator cap.

*****************************************************

Measurement steps:

●

Install the radiator cap tester

and adapter

onto the radiator cap

●

Apply the specified pressure for ten seconds
and make sure that there is no drop in
pressure.

*****************************************************
4.Check:

●

Radiator fan
Damage

→

Replace.

Malfunction

→

Check and repair.

Refer to “COOLING SYSTEM” in CHAPTER
9.

Radiator cap opening pressure:

93.7 ~ 122.6 kPa
(0.937 ~ 1.226 kg/cm

13.32 ~ 17.43 psi)

Radiator cap tester:

P/N. YU-24460-01, 90890-01325

Adapter:

P/N. YU-33984, 90890-01352

5 - 5

COOL

THERMOSTAT

Order

Job name/Part name

Q’ty

Remarks

Removing the thermostat

Remove the parts in the order below.

Seat and fuel tank side panel (right)

Refer to “SEAT AND SIDE PANELS” in
CHAPTER 3.

Coolant

Drain.
Refer to “CHANGING THE COOLANT” in
CHAPTER 3.

Radiator inlet hose

Thermostat cover

Thermostat

For installation, reverse the removal
procedure.

5 - 6

COOL

THERMOSTAT

CHECKING THE THERMOSTAT

1.Check:

●

Thermostat

Does not open at 63.5 ~ 66.5 °C (146.3 ~
151.7 °F)

→

Replace.

*****************************************************

Checking steps:

●

Suspend the thermostat in a container filled
with water.

●

Slowly heat the water.

●

Place a thermometer in the water.

●

While stirring the water, observe the
thermostat and thermometer’s indicated
temperature.

*****************************************************

Thermostat

Thermometer

Water

Container

Fully closed

Fully open

NOTE:

If the accuracy of the thermostat is in doubt,
replace it. A faulty thermostat could cause
serious overheating or overcooling.

2.Check:

●

Thermostat cover
Cracks/damage

→

Replace.

INSTALLING THE THERMOSTAT

1.Install:

●

Thermostat

●

Thermostat cover

NOTE:

Install the thermostat with its breather hole

toward the projection

2.Fill:

●

Cooling system
(with the specified amount of the
recommended coolant)
Refer to “CHANGING THE COOLANT” in
CHAPTER 3.

3.Check:

●

Cooling system
Leak

→

Repair or replace any faulty part.

Yamaha YFM45FAR, YFM450FAR. Service Manual - part 14