Snowmobile Yamaha FX10X, FX10RTX, FX10RTRX, FX10RTRAX, FX10MTX, FX10MTRX, FX10MTRAX. Manual - part 63

5-72

ENG

CRANKSHAFT AND BALANCER SHAFT

Measurement steps:

CAUTION:

Do not interchange the crankshaft journal bear-
ings. To obtain the correct crankshaft-journal-
to-crankshaft-journal-bearing clearance and
prevent engine damage, the crankshaft journal
bearings must be installed in their original posi-
tions.

• Clean the crankshaft journal bearings, crank-

shaft journals, and bearing portions of the
crankcase.

• Place the upper crankcase upside down on a

bench.

• Install the crankshaft journal upper bearings 1

and the crankshaft into the upper crankcase.

NOTE:

Align the projections 

a of the crankshaft journal

upper bearings with the notches 

b in the crank-

case.

• Put a piece of Plastigauge

®

 

b on each crank-

shaft journal.

NOTE:

Do not put the Plastigauge

®

 over the oil hole in the

crankshaft journal.

b

• Install the crankshaft journal lower bearings 2

into the lower crankcase and assemble the
crankcase halves.

NOTE:

• Align the projections 

c of the crankshaft journal

lower bearings with the notches 

d in the crank-

case.

• Do not move the crankshaft until the clearance

measurement has been completed.

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ENG

CRANKSHAFT AND BALANCER SHAFT

• Tighten the bolts in the order of the embossed

numbers on the crankcase.
Refer to “INSTALLATION” in “CRANKCASE” on
page 5-54.

• Remove the lower crankcase and the crank-

shaft journal lower bearings.

• Measure the compressed Plastigauge

®

 width 

e

on each crankshaft journal.
If the clearance is out of specification, select
replacement crankshaft journal bearings.

e

7. Select:

• Crankshaft journal bearings (J1 ~ J4)

NOTE:

• The numbers 

È stamped into the crankshaft web

and the numbers 

É stamped into the lower

crankcase are used to determine the replace-
ment crankshaft journal bearing sizes.

• “J1 ~ J4” refer to the bearings shown in the crank-

shaft web and lower crankcase illustration.

• If “J1 ~ J4” are the same, use the same size for

all of the bearings.

Selection of bearings:
For example, if the crankcase “J1” and crankshaft
web  “J1” numbers are “6” and “1” respectively,
then the bearing size for “J1” is:

Bearing size for J1:

J1 (crankcase) – J1 (crankshaft web) + 2 
= 6 – 1 + 2 = 7

CRANKSHAFT JOURNAL BEARING COLOR 

CODE

2

black

3

brown

4

green

5

yellow

6

pink

7

red

8

white

J1

J2

J3

J4

2 2 2 1

3 2 2

J1

J3

J2

J4

È

J4 J3 J2 J1 É

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ENG

CRANKSHAFT AND BALANCER SHAFT

INSTALLATION

1. Install:

• Balancer driven gear 1 
• Balancer shaft 2 

NOTE:

• Face the punch mark 

a on the balancer driven

gear inward.

• Align the projection 

b on the balancer shaft with

the slot 

c in the balancer driven gear.

1

2

c

b

a

2. Install:

• Water pump drive gear 1 

NOTE:

Align the punch mark 

a on the water pump gear

with the shorter spline 

b on the balancer shaft end.

b

1

a

b

3. Install:

• Right balancer weight 1 
• Left balancer weight 2 
• Washers
• Lock washers
• Balancer weight bolts

NOTE:

Align the punch mark 

a on the balancer weight

with the shorter spline 

b on the balancer shaft end.

a

1

b

New

a

2

b

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ENG

CRANKSHAFT AND BALANCER SHAFT

4. Tighten:

• Balancer weight bolts 1 

NOTE:

Place a wood 

a between the balancer weight 2

and crankcase.

5. Bend the lock washer tab.

T

 

R

.

.

Balancer weight bolt:

35 Nm (3.5 m · kg, 25 ft · lb)

1

a

2

1

a

2

6. Install:

• Crankshaft journal upper bearings

(into the upper crankcase)

• Crankshaft journal lower bearings

(into the lower crankcase)

NOTE:

• Align the projections 

a on the crankshaft journal

bearings with the notches 

b in the crankcase.

• Be sure to install each crankshaft journal bearing

in its original place.

7. Install:

• Bearing 1 

(to the primary sheave drive shaft assembly
2)

NOTE:

Be sure to install the bearing so that its hole 

a is

near the bearing edge that is facing away from the
primary sheave drive shaft assembly.

a

1

2