Snowmobile Yamaha Phazer PZ50 (2007-2008 year). Manual - part 61

6-3

COOL

RADIATOR AND HEAT EXCHANGER

INSPECTION

1. Inspect:

• Coolant hoses
• Heat exchanger
• Oil cooler
• Coolant pipes

Cracks/damage 

→ Replace.

2. Check:

• Radiator fins

Obstruction 

→ Clean.

Apply compressed air to the rear of the radia-
tor. 
Damage 

→ Repair or replace.

NOTE:

_ 

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

3. Check:

• Radiator fan (PZ50VT/PZ50MP)

Damage 

→ Replace.

Malfunction 

→ Check and repair.

4. Measure:

• Filler cap opening pressure

Cap opens with a pressure below the speci-
fied pressure 

→ Replace.

Measurement steps:

• Attach the cooling system tester 1 to the cool-

ant filler cap 2.

• Apply the specified pressure for 10 seconds

and make sure there is no pressure drop.

Filler cap opening pressure:

93.3 ~ 122.7 kPa
(0.93 ~ 1.23 kg/cm

2

, 13.2 ~ 17.5 psi)

Cooling system tester:

90890-01325, YU-24460-01

Adapter:

90890-01352, YU-33984

6-4

COOL

RADIATOR AND HEAT EXCHANGER

INSTALLATION

1. Install:

• Heat exchanger

Use the rivet gun.

2. Install:

• O-ring
• Oil cooler 1 

NOTE:

Install the oil cooler with the manufacturer’s mark
a facing down.

T

 

R

.

.

Oil cooler bolt:

10 Nm (1.0 m · kg, 7.2 ft · lb)
LOCTITE

®

1

a

6-5

COOL

THERMOSTAT

THERMOSTAT

Order

Job name/Part name

Q’ty

Remarks

Thermostat disassembly

Remove the parts in the order listed below.

1 

Coolant temperature sensor coupler

1

Disconnect.

2 Coolant 

temperature 

sensor

1

3 Radiator 

inlet 

hose

1

Disconnect.

4 

Throttle body heater inlet hose

1

Disconnect.

5 

Oil cooler outlet hose

1

Disconnect.

6 

Water pump inlet hose

1

Disconnect.

7 

Coolant reservoir outlet hose

1

Disconnect.

8 Engine 

outlet 

hose

1

Disconnect.

9 Thermostat 

housing 

cover

1

0 Thermostat

1

A Thermostat 

housing

1

For assembly, reverse the disassembly pro-
cedure.

9

0

A

1

3

6

5

2

4

7

8

10 Nm (1.0 m 

•

 kg, 7.2 ft 

•

 lb)

È:   

23 Nm (2.3 m 

•

 kg, 17 ft 

•

 lb)

É:   

B

New

È

6-6

COOL

THERMOSTAT

INSPECTION

1. Inspect:

• Thermostat

Does not open at 80 ~ 84 °C (176 ~ 183 °F)
→ Replace.

Inspection 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.

1 Thermometer
2 Water
3 Thermostat
4 Container
È Fully closed
É Fully open
Ê More than 7 mm (0.28 in)

NOTE:

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

2. Inspect:

• Thermostat housing cover
• Thermostat housing

Cracks/damage 

→ Replace.

INSTALLATION

1. Install:

• Thermostat

(into the thermostat housing)

NOTE:

Install the thermostat with its breather hole 

a

aligned with the this place 

b on the thermostat

housing.

2. Install:

• Thermostat housing cover
• Thermostat housing cover bolts

T

 

R

.

.

Thermostat housing cover bolt:

10 Nm (1.0 m · kg, 7.2 ft · lb)

a

b