CFMoto ATV CF500/CF500-A. Service Manual

16. Carburetor

If float height is not within the specification, check

the valve seat and needle valve;

If either of valve seat or needle valve is worn,

replace both;

If both are fine, adjust float height by bending the

float tang

①

on the float;

Measure float height again till it’s within the

specification

Fuel Level

Place carburetor on a level surface. Connect fuel

level gauge

①

with drain pipe

②

;

Tool: Fuel Level Gauge

Loosen drain screw

③

Keep fuel level gauge vertical next to the float

chamber line and read the fuel level “a”

Fuel Level: 3.5

0.5mm

If the fuel level is not within the specification, adjust
the fuel level;

Remove

carburetor

Check valve seat and needle valve

If either of valve seat or needle valve is worn,

replace both;

If both are fine, adjust float height by bending the

float tang

①

on the float;

Install

carburetor

Check again the fuel level

Carburetor Assembly

Reverse the disassembly procedure for assembly

16-5

16. Carburetor

Carburetor Installation

①

-vacuum breather hose

②

-starter cable

③

-carburetor joint (engine intake manifold))

④

-throttle valve cover

⑤

-throttle cable

⑥

-Carburetor joint (air filter)

⑦

-carburetor

⑧

-drain hose

⑨

-fuel inlet hose

Note:

Align the installation mark of carburetor and carburetor joint

6. Carburetor Parameters

Type

Aperture No.

Throat size (mm)

Pilot (r/min)

Float height (mm)

Fuel level (mm)

Main jet (MJ)

Main air jet (MAJ)

Jet needle (JN)

Needle jet (NJ)

Pilot jet (PJ)

Pilot screw (PS)

Pilot air jet1 (PAJ1)

Pilot air jet2 (PAJ2)

MIKUNI BSR36-89

07G0

36mm

1300 r/min

100 r/min

10±1

3.5±0.5

N102221-130#

MD13/24-35#

J8-5E26

785-401011-P-OM

N224103-22.5#

604-16013-1A

MD13/24-65#

N211100-165#

6-6

17. Cooling and Lubrication System

Cooling System Illustration…………………………………………17-2

Engine Coolant………………………………………………………17-3

Inspection of Cooling Circuit……………………….………………17-3

Inspection and Cleaning of Radiator and Water Hoses…………17-4

Inspection of Fan Motor……………………………………….……17-5

Inspection of Water Temperature Sensor…………………………17-6

Inspection of Thermostat……………………………………………17-6

Water Pump……………………………………………………….…17-7

Water Pump Removal and Disassembly……………………17-7
Inspection………………………………………………………17-9
Water Pump Assembly and Installation………..……………17-10

Lubrication System Illustration………………………………..……17-14

Inspection of Lubrication System……………………….…………17-15

Inspection of Oil Pump and Relief Valve……………………….…17-15

17-1

17. Cooling and Lubrication System

Engine Coolant

The coolant used in cooling system is a mixture of 50%
distilled water and 50% ethylene glycol antifreeze. This
50:50 mixture provides the optimized corrosion
resistance and fine heat protection. The coolant will
protect the cooling system from freezing at temperature
above –30

℃

. If the vehicle will be operated at the

environmental temperature below –30

℃

, the mixing ratio

of coolant should be increased to 55% or 60% according
to the figure on the right.

Note

:Use high quality ethylene glycol base antifreeze

and mixed with distilled water. Never mix an alcohol base
antifreeze and different brands of antifreeze;
The ratio of antifreeze should not be more than 60% or
less than 50%;
Do not use anti-leak additive;

Warning !

DO NOT open radiator cap when the engine is still

hot. Or you may be injured by scalding fluid or
steam;

Coolant is harmful. DO NOT swallow or stain your

skin or eyes with coolant. In case of accidental
swallow or stains, flush with plenty of water and
consult the doctor immediately.

Keep coolant away from reach of children.

Inspection of Cooling Circuit

Remove radiator cap

①

and connect tester

② to

filler.

Warning!

Do not open the radiator cap when the engine is still hot.

Give a pressure of 120 kPa and check if the cooling

system can hold this pressure for 10 seconds.

If the pressure drops during this 10 seconds, it

indicates that the there is leakage with the cooling
system. In this case, check the complete system
and replace the leaking parts or components.

Warning!

When removing the radiator cap tester, put a rag on

the filler to prevent splash of coolant.

Warning!

Do not allow a pressure to exceed the radiator cap

release pressure.

17-3

17. Cooling and Lubrication System

Inspection and Cleaning of Radiator and
Water Hoses

Radiator Cap

Remove radiator cap

①

Install radiator cap to cap tester

②

Slowly increase pressure to 93.3-122.7 kPa and

check if the cap can hold the pressure for at least
10 seconds.

If the cap cannot meet the pressure requirement,

replace it.

Radiator Cap Valve Opening Pressure:
Standard: 93.9-122.9 kPa
Tool: Radiator Cap Tester

Radiator Inspection and Cleaning

Remove dirt or trash from radiator with compressed

air;

Correct the radiator fins with a small screwdriver;

Radiator Hose Inspection

Check radiator hoses for leakage or damage.

Leakage or Damage:

→

Replace

Check tightening of clamps. Replace the clamps if

necessary;

After inspection and cleaning of radiator and hoses,

check coolant level. Fill coolant if necessary.

17-4

17. Cooling and Lubrication System

Inspection of Fan Motor

Remove fan motor from radiator

Turn the vanes and check if they can turn smoothly;

Check fan motor: Make sure that the battery applies

12 volts to the motor and the motor will run at full
speed while the ammeter shall indicate the ampere
not more than 5A.

If the motor does not run or the ampere exceeds the

limit, replace the motor.

Installation: Apply a little thread locker to the bolts

and tighten to the specified torque.

Fan Motor Bolt Tightening Torque: 10N.m

Inspection of Thermoswitch

Remove

thermoswitch

Check the thermoswitch for closing or opening by

testing it at the bench as illustrated. Connect the
thermoswitch

①

to the circuit tester, place it in a

vessel with engine oil. Place the vessel above a
stove.

Heat the oil to raise the temperature slowly and take

the reading from thermometer

②

when the

thermoswitch closes and opens.

Tool: ammeter
Thermoswitch Operating Temperature
Standard: (OFF-ON): Approx. 88

℃

(ON-OFF): Approx. 82

℃

Note:

Avoid sharp impact on thermoswitch.

Avoid contact of thermoswitch with thermometer or

vessel

Installation:

Use a new O-ring

③

and tighten the

thermoswitch to the specified torque:

Thermoswitch Tightening Torque: 17N.m

Check coolant level after installation of

thermoswitch. Fill coolant if necessary.

17-5

17. Cooling and Lubrication System

Inspection of Water Temperature Sensor

Place a rag under water temperature sensor

①

and

remove it from cylinder head.

Check the resistance of water temperature sensor

as illustrated on the right. Connect the temperature
sensor

②

to the circuit tester, place it in a vessel

with engine oil. Place the vessel above a stove.

Heat the oil to raise the temperature slowly and take

the reading from thermometer

③

and ohmmeter

④

Water Temperature and Resistance

Temperature( )

℃

50 80 100 120

Resistance(

Ω

)

154±16 52±4 27±3 16±2

Installation:

Apply a little thread locker and install it to

the cylinder head by tightening to the specified torque.

Water Temperature Sensor
Tightening Torque: 10N.m

Note:

Avoid sharp impact on temperature sensor

Avoid contact of temperature sensor with

thermometer or vessel

After installation, check the coolant level. Fill

coolant if necessary.

Inspection of Thermostat

Remove thermostat case

Remove

thermostat

17-6

17. Cooling and Lubrication System

Check thermostat pellet for cracks

Test the thermostat in the following steps:

Pass a string between thermostat flange as

illustrated on the right;

Immerse the thermostat in a beaker with water.

Make sure that the thermostat is in the suspended
position without contact to the vessel. Heat the
water by placing the beaker above a stove and
observe the temperature rise on a thermometer;

Take the temperature reading from thermometer

when the thermostat valve opens.

Thermostat Valve Opening Temperature: 68-74

℃

Keep heating the water to raise the water

temperature.

Just when the water temperature reaches the

specified value, the thermostat valve should have
been lifted by 3.5-4.5mm

Installation:

Reverse the removal procedure for installation.

Apply coolant to the rubber seal of thermostat.

Install thermostat case. Tighten to the specified

torque:

Tightening Torque: 10N.m

Water Pump

Removal and Disassembly

Remove engine left side cover;

Drain coolant (

→

11-10)

Note

: Before draining coolant, check water pump for oil

or coolant leakage. In case of oil leakage, check the
water pump oil seal, O-ring. In case of coolant leakage,
check the water seal.

17-7

17. Cooling and Lubrication System

Remove clamps and water hoses

Release bolts and remove water pump

Remove

O-ring

Note:

Do not reuse the O-ring.

Remove the overflow tube

Release water pump cover screws, water pump

cover and gasket

Remove E-ring and impeller

Remove seal ring

①

and rubber seal

②

17-8

17. Cooling and Lubrication System

Remove mechanical seal with special tool

Note:

The mechanical seal does not need to be

removed if there is no abnormal condition.

Note:

Do not reuse a removed mechanical seal

Put a rag on the water pump body

Remove oil seal.

Note:

The oil seal does not need to be removed if there

is no abnormal condition

Note:

Do not reuse a removed oil seal

Remove bearing with special tool.

Note:

The bearing does not need to be removed if

there is no abnormal noise.

Note:

Do not reuse a removed bearing.

Inspection of Water Pump

Bearing

Check the play of bearing by hand while it is still in

the water pump body;

Turn inner race of bearing to check for abnormal

noise and smooth rotation;

Replace the bearing if there is abnormal condition;

Mechanical Seal

Check mechanical seal for damage, pay special

attention to the seal face;

In case of leakage or damage, replace the

mechanical seal. If necessary, also replace the seal
ring.

17-9

17. Cooling and Lubrication System

Oil Seal

Check oil seal for damage. Pay special attention to

the oil seal lip;

In case of damage or leakage, replace the oil seal;

Water Pump Body

Check the mating mace of water pump body with

bearing and mechanical seal.

Damage:

→

Replace

Impeller

Check the impeller and shaft for damage.

Damage:

→

Replace

Assembly and Installation of Water Pump

Install oil seal with special tool;

Tool: Oil Seal Installer

Note:

The stamped mark on the oil seal faces outside

Apply a little grease to the oil seal lip.

17-10

17. Cooling and Lubrication System

Install mechanical seal with a suitable socket

wrench

Note:

Apply sealant to side “A” of mechanical seal

Install bearing with special tool

Tool: Bearing Installer

Note:

The stamped mark on the bearing faces outside.

Install seal ring to impeller

Clean off the oil and grease from mechanical seal

and install it into the impeller.

Note:

“A” side of mechanical seal faces impeller

Apply grease to impeller shaft

Install impeller shaft to water pump body.

17-11

17. Cooling and Lubrication System

Install E-ring to water pump shaft;

Install new gasket to water pump body;

Install water pump cover and tighten the bolts and

bleed bolt.

Water Pump Cover Bolts Tightening Torque: 6N.m

Check impeller for smooth turning.

Install the new O-ring

Note:

Use the new O-ring to prevent oil leakage;

Apply grease to O-ring

17-12

17. Cooling and Lubrication System

Install water pump and tighten the bolts to the

specified torque;

Water pump bolts tightening torque: 10N.m

Note

: Set the water pump shaft slot end “B” to oil pump

shaft flat side “A”.

Connect water hoses

Add

coolant

Install left side cover

17-13

CFMoto ATV CF500/CF500-A. Service Manual - part 15