Snowmobile Yamaha Phazer PZ50W, PZ50GTW, PZ50FXW, PZ50MW, PZ50VTW, PZ50MPW. Manual - part 58

5-69

ENG

CRANKCASE

13. Select:

• Crankshaft journal bearings (J1 ~ J3)

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 ~ J3” refer to the bearings shown in the crank-

shaft illustration.

• If “J1 ~ J3” 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 “4” and “2” respectively,
then the bearing size for “J1” is:

14. Measure:

• Crankshaft-pin-to-big-end-bearing clearance

Out of specification 

→ Replace the big end

bearings.

Bearing size for J1:

J1 (crankcase) – J1 (crankshaft web)
– 1 = 4 – 2 – 1 = 1 (blue)

CRANKSHAFT JOURNAL BEARING COLOR 

CODE

0

white

1

blue

2

black

3

brown

4

green

Crankshaft-pin-to-big-end-bearing 
clearance:

0.034 ~ 0.058 mm
(0.0013 ~ 0.0023 in)

J1

J2

J3

J1

J3 J2

2 1 2

2 2

BA

C

È

J3 J2 J1 É

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CRANKCASE

Measurement steps:

CAUTION:

Do not interchange the big end bearings and
connecting rods. To obtain the correct crank-
shaft-pin-to-big-end-bearing clearance and pre-
vent engine damage, the big end bearings must
be installed in their original positions.

• Clean the big end bearings, crankshaft pins,

and bearing portions of the connecting rods.

• Install the big end upper bearing into the con-

necting rod and the big end lower bearing into
the connecting rod cap.

NOTE:

Align the projections 

a on the big end bearings

with the notches 

b in the connecting rod and con-

necting rod cap.

• Put a piece of Plastigauge

®

  1 on the crank-

shaft pin.

• Assemble the connecting rod halves.

NOTE:

• Do not move the connecting rod or crankshaft

until the clearance measurement has been com-
pleted.

• Apply molybdenum disulfide grease onto the

bolts, threads, and nut seats.

• Make sure that the “Y” mark 

c on the connecting

rod faces towards the right side of the crankshaft.

• Make sure that the characters 

d on both the con-

necting rod and connecting rod cap are aligned.

1

5F

Y

d

c

d

5 F

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ENG

CRANKCASE

• Tighten the connecting rod bolts.

• Replace the connecting rod bolts with new

ones.

CAUTION:

Tighten the connecting rod bolts using the
plastic-region tightening angle method. Always
install new bolts.

Tightening steps:

• Clean the connecting rod bolts.
• Tighten the connecting rod bolts.
• Put a mark 

e on the corner of the connecting

rod bolt 1 and the connecting rod 2.

• Tighten the connecting rod bolt further to reach

the specified angle (120 ~ 130°).

WARNING

When the bolt is tightened more than the speci-
fied angle, do not loosen the bolt and then
retighten it.
Replace the bolt with a new one and perform
the procedure again.

CAUTION:

• Do not use a torque wrench to tighten the bolt

to the specified angle.

• Tighten the bolt until it is at the specified

angles.

• Remove the connecting rod and big end bear-

ings.

• Measure the compressed Plastigauge

®

 width 

f

on the crankshaft pin.
If the clearance is out of specification, select
replacement big end bearings.

T

 

R

.

.

Connecting rod bolt:

1st: 20 Nm (2.0 m · kg, 14 ft · lb)
Final: Specified angle 120 ~ 130°

f

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CRANKCASE

15. Select:

• Big end bearings (P1 ~ P2)

NOTE:

• The numbers 

È stamped into the crankshaft web

and the numbers 1 on the connecting rods are
used to determine the replacement big end bear-
ing sizes.

• “P1” ~ “P2” refer to the bearings shown in the

crankshaft illustration.

Selection of bearings:

• For example, if the connecting rod “P1” and the

crankshaft web “P1” numbers are “5” and “2”
respectively, then the bearing size for “P1” is:

16. Inspect:

• Crankcase:

Cracks/damage 

→ Replace.

NOTE:

• Thoroughly wash the crankcase halves in a mild

solvent.

• Thoroughly clean all the gasket surfaces and

crankcase mating surfaces.

• Oil delivery passages

Obstruction 

→ Blow out with compressed air.

17. Inspect:

• Bearings

Clean and lubricate the bearings, then rotate
the inner race with your finger.
Rough movement 

→ Replace.

18. Inspect:

• Timing chain

Damage/stiffness 

→ Replace the chain and

sprocket as a set.

19. Inspect:

• Timing chain guide (intake side)

Damage/wear 

→ Replace the timing chain

guide.

Bearing size for “P1”:

“P 1” (connecting rod) – “P1” (crankshaft 
web) – 1 = 5 – 2 – 1 = 2 (black)

BIG END BEARING COLOR CODE

0

white

1

blue

2

black

3

brown

P1

P2

P1

P2

2 1 2

2 2

BA

C

È

1

5 F