CFMoto motorcycle CF650NK. Service Manual - part 19

4-18 COOLING SYSTEM

Hose and Pipes

Hose Installation 

●

 Install the hoses and pipes, being careful to 

   follow bending direction. Avoid sharp bending, 
   kinking, 

fl

 attening or twisting. 

●

 Run the hoses (see Cable, Wire, and Hose 

   Routing section in the Appendix chapter). 

●

 Install the clamp [A] as near as possible to the 

   hose end to clear the raised rib of the 

fi

 tting. This 

   will prevent the hoses from working loose.

○

 The clamp screws should be positioned correctly 

   to prevent the clamps from contacting the other 
   parts.
 

  Torque - Radiator Hose Clamp Screws: 2.0 

   N·m (0.20 kgf·m, 17 in·lb)

Hose Inspection 

●

 Refer to the Radiator Hose Damage and 

   Installation Condition Inspection in the Periodic 
   Maintenance chapter.

COOLING SYSTEM 4-19

Coolant Temperature Sensor

CAUTION

The coolant temperature sensor should never 

be allowed to fall on a hard surface. Such a 

shock to the water temperature sensor can 

damage it.

Coolant Temperature Sensor Removal/

Installation 

● Refer to the Water Temperature Sensor Removal/

 

   Installation in the Fuel System (EFI) chapter.

   Coolant Temperature Sensor [A]

Coolant Temperature Sensor Inspection 

● Refer to the Water Temperature Sensor 

 

   Inspection in the Electrical System chapter.

ENGINE TOP END 5-1

Engine Top End

Table of Contents

Exploded view............................................................

5-2

Specifi cations.............................................................

5-6

Special tools and sealant...........................................

5-8

Cylinder head cover...................................................

5-10

Cylinder head cover removal................................

5-10

Cylinder head cover installation............................

5-10

Timing chain tensioner...............................................

5-12

Timing chain tensioner removal............................

5-12

Timing chain tensioner installation........................

5-12

Camshaft/Timing chain..............................................

5-14

Camshaft removal................................................

5-14

Camshaft installation............................................

5-15

Camshaft and sprocket assembly.........................

5-17

Camshaft/Camshaft cap wear..............................

5-18

Camshaft run-out..................................................

5-18

Cam wear.............................................................

5-19

Timing chain removal...........................................

5-19

Cylinder head.............................................................

5-20

Cylinder compression measurement....................

5-20

Cylinder head removal..........................................

5-21

Cylinder head installation.....................................

5-22

Cylinder head wear..............................................

5-23

Valves........................................................................

5-24

Valve clearance inspection...................................

5-24

Valve clearance adjustment ................................

5-24

Valve removal......................................................

5-24

Valve installation..................................................

5-24

Valve guide removal.............................................

5-25

Valve guide installation.........................................

5-25

Valve-to-guide clearance measurement         
     (Wobble Method)..................................................

5-26

Valve seat inspection...........................................

5-27

Valve seat repair...................................................

5-27

Cylinder/Piston..........................................................

5-28

Cylinder removal..................................................

5-28

Cylinder installation..............................................

5-28

Piston removal.....................................................

5-29

Piston installation.................................................

5-30

Cylinder wear.......................................................

5-31

Piston wear..........................................................

5-31

Piston ring/Piston ring groove wear......................

5-31

Piston ring groove width.......................................

5-32

Piston ring thickness............................................

5-33

Piston ring cut clearance......................................

5-33

Intake manifold..........................................................

5-34

Intake manifold installation...................................

5-34

Exploded View

5-2 ENGINE TOP END 

ENGINE TOP END 5-3

Item

Fastner

Torque

Remarks

N·m

kgf·m

ft·lb

1

Air Suction Valve Cover Bolts

1.0

87 in·lb

2

Cylinder Head Cover Bolts

1.0

87 in·lb

3

Camshaft Cap Bolts

 12

1.2

106 in·lb

S

      4

Cylinder Head Bolts (M10 New Bolts)

 54

55

40

MO,S

Cylinder Head Bolts (M10 Used Bolts)

 49

50

36

MO,S

5

Cylinder Head Bolts (M6)

 12

1.2

106 in·lb

S

6

Throttle Body Holder Bolts

 12

1.2

106 in·lb

7

Camshaft Chain Guide Bolts

 20

2.0

15

L

8

Camshaft Chain Tensioner Mounting Bolts

1.0

87 in·lb

9

Tensioner Nut

 20

2.0

15

10

Spark plug

 15

1.5

11

11

Camshaft Sprocket Bolts

 15

1.5

11

L

12

Baf

fl

 e Plate Bolts

6

0.60

52 in·lb

L

13

Baf

fl

 e Plate Bolts

6

0.60

52 in·lb

L:     Apply a non-permanent locking agent.

M:    Apply molybdenum disul

fi

 de grease.

MO: Apply molybdenum disul

fi

 de oil solution.

        (mixture of the engine oil and molybdenum disul

fi

 de grease in a weight ratio 10 : 1) 

R:    Replacement Parts

S:    Follow the speci

fi

 ed tightening sequence.

         SS:Apply silicone sealant.

10

10

10

ENGINE TOP END 5-3

5-4 ENGINE TOP END 

Exploded View

Item No.

Fastner

Torque

Remarks

N·m

kgf·m

ft·lb

1

Cylinder Bolt (M8)

27.5

2.8

20

MO,S

2

Cylinder Nut (M10)

49

5.0

36

MO,S

3

Cylinder Bolts (M6)

12

1.2

106in·lb

S

4

Exhaust Pipe Manifold Holder Nuts

17

1.7

12

5

Muf

fl

 er Body Mounting Bolt (Front)

20

2.0

15

6

Muf

fl

 er Body Mounting Bolt (Rear)

20

2.0

15

7:      “A” marked side faces up.

8:     “A”marked side faces up

9:      Hollow mark faces forward.

MO:  Apply molybdenum disul

fi

 de oil solution.

         (mixture of the engine oil and molybdenum disul

fi

 de grease in a weight ratio 10 : 1) 

R:      Replacement Parts

S:      Follow the speci

fi

 ed tightening sequence.

ENGINE TOP END 5-5

5-6 ENGINE TOP END 

Technical Speci

fi

 cations

Item

Standard data

Service limit

Camshafts

Cam Height:
   Exhaust

35.843-35.957mm(1.4111~1.4156in.)

35.74mm(1.4071in.)

   Intake

36.543~36.657mm

36.44mm(1.4346in.)

(1.4387~1.4432in.)

Camshaft Journal, Camshaft
Cap Clearance

0.028~0.071mm(0.0011-0.0028in.)

0.16mm(0.0063in.)

Camshaft Journal Diameter

23.950~23.972mm
(0.9429~0.9438in.)

23.92mm(0.942in.)

Camshaft Bearing Inside
Diameter

24.000~24.021mm
(0.9449~0.9457in.)

24.08mm(0.948in.)

Camshaft Runout(wear)

0.02mm(0.0008in.)

0.1mm(0.004in.)

Cylinder Head

Cylinder Compression 
pressure

961~1471kPa(9.8-15.0kgf/cm

2

)

at400r/min(rpm)

–––

Cylinder Head Flatness

–––

0.05mm(0.002in.)

Valves

Valve Clearance:
    Exhaust

0.20~0.26mm(0.0078-0.0102in.)

–––

    Intake

0.08~0.13mm(0.0031-0.0051in.)

–––

Valve Stem Bend

0.01mm(0.0004in.)

0.05mm(0.002in.)

Valve Stem Diameter:
    Exhaust

4.455~4.470mm(0.1754-0.1760in.)

4.44mm(0.175in.)

    Intake

4.475~4.490mm(0.1762-0.1768in.)

4.46mm(0.176in.)

Valve Guide Inside Diameter:

Exhaust

4.500~4.512mm(0.1772-0.1776in.)

4.58mm(0.180in.)

Intake

4.500~4.512mm(0.1772-0.1776in.)

4.58mm(0.180in.)

Valve/Valve Guide Clearance
(Wobble Method):

Exhaust

0.07~0.14mm(0.0028-0.0055in.)

0.27mm(0.0106in.)

Intake

0.02~0.08mm(0.0008-0.0032in.)

0.22mm(0.0087in.)

Valve Seating Surface:

Width:

Exhaust

0.5~1.0mm(0.020-0.039in.)

–––

Intake

0.5~1.0mm(0.020-0.039in.)

–––

Outside Diameter:

Exhaust

26.6~26.7mm(1.087-1.094in.)

–––

Intake

31.2~31.3mm(1.283-1.291in.)

–––

ENGINE TOP END 5-7

Item

Standard data

Service limit

Valve Spring Free Length:

Exhaust

41.6mm(1.638in.)

40mm(1.575in.)

Intake

41.6mm(1.638in.)

40mm(1.575in.)

Cylinder & Pistons

Cylinder Inside Diameter

82.98-83.00mm(3.2669~3.2677in.)

83.10mm(3.2716in.)

Piston(skirt) Diameter

82.975-82.995mm(3.2667~3.2675in.)

82.82mm(3.2606in.)

Piston/Cylinder Clearance

0.010-0.037mm(0.0004-0.0015in.)

–––

Piston Ring/Groove Clearance:

Top

0.04~0.075mm(0.00157-0.00295in.)

0.17mm(0.0067in.)

Second

0.02~0.06mm(0.0008-0.0024in.)

0.16mm(0.0063in.)

Piston Ring Groove Width:

Top

0.92~0.94mm(0.0362-0.0370in.)

1.02mm(0.040in.)

Second

1.01~1.03mm(0.0398-0.0406in.)

1.11mm(0.044in.)

Piston Ring Thickness:

Top

0.865~0.88mm(0.0341-0.03465in.)

0.80mm(0.031in.)

Second

0.97~0.99mm(0.0382-0.0390in.)

0.90mm(0.035in.)

Piston Ring End Gap:

Top

0.15~0.30mm(0.0059-0.0118in.)

0.7mm(0.028in.)

Second

0.30~0.45mm(0.0118-0.0177in.)

0.8mm(0.031in.)

5-8 ENGINE TOP END 

Compression Gaug

e

Valve Seat Cutter, 60

o

-Ø30:

Valve Spring Compressor Assembly

Valve Seat Cutter Holder Bar:

Valve Seat Cutter, 45

o

-Ø35:

Valve Seat Cutter, 45

o

-Ø30:

Valve Seat Cutter, 32

o

-Ø30:

Valve Seat Cutter, 55

o

-Ø35:

Valve Seat Cutter, 32

o

-Ø35:

Valve Spring Compressor Adapter, Ø21:

ENGINE TOP END 5-9

Compression Gauge Adapter, M10×1.0:

Piston Pin Puller:

Valve Seat Cutter Holder, Ø4.5 :

Piston Pin Puller Adapter C:

Valve Guide Arbor, Ø4.5 :

Silicone Sealant :

Valve Guide Reamer, Ø4.5 :

5-10 ENGINE TOP END 

Cylinder Head Cover

Cylinder Head Ccover Removal

●

 Remove:

  1.  Fuel Tank (see Fuel Tank Removal in the Fuel  
       System (EFI) chapter)
   2. Housing of air 

fi

 lter (see Air 

fi

 lter Housing 

       Removal in the Fuel System (EFI) chapter)
   3. Ignition coil[C]
   4. Baf

fl

 e plate[D]

   5. Throttle cables[E]
   6. Clutch Cable Holder [F] with Bolt [G]
   7. Cylinder Head Cover Bolts [H]
   8. Cylinder Head Cover [I]

Cylinder Head Cover Installation

●

 Replace the head cover gasket [A] with a new 

   one.

●

 Apply silicone sealant [B] to the cylinder head as 

   shown.

●

 Install gaskets of spark plug hole [C].

●

 Install: 

   Washers [A]
   Cylinder Head Cover Bolts [B]

●

 Install the washers with metal side [C] faces 

   upward.

●

 Tighten bolt of cylinder head cover.

  

 Torque - Cylinder Head Cover Bolts : 10 N·m

ENGINE TOP END 5-11

Cylinder Head Cover

●

 Install the baf

fl

 e plate [A].

○

 Put the insulators [B] under the baf

fl

 e plate and 

   the washers [C] on the baf

fl

 e plate.

○

 Apply a non-permanent locking agent to 

   the baf

fl

 e plate bolts and tighten them.

    Torque - Baf

fl

 e Plate Bolts : 6 N·m

5-12 ENGINE TOP END 

Camshaft Chain Tensioner

Camshaft Chain Tensioner Removal

CAUTION

This is a non-return type camshaft chain  
tensioner. The push rod does not return 
to its original position once it moves out 
to take up camshaft chain slack. Observe 
all the rules listed below: 
When removing the tensioner, do not  
take out the mounting bolts  only halfway. 
Retightening the mounting bolts from this 
position could damage the tensioner and 
the camshaft chain. Once the bolts are 
loosened, the tensioner must be removed 
and reset as described in "Camshaft 
Chain Tensioner Installation". Do not turn 
over the crankshaft while the tensioner is 
removed.  This could upset the camshaft 
chain timing, and damage the valves.

●

 Remove:

   1.Cap Bolt [A]
   2. Washer[B] 
   3. Spring [C]

●

 Remove the mounting bolts [D] and take off the 

   camshaft chain tensioner.

Camshaft Chain Tensioner Installation

●

 Release the stopper [A] and push the push rod [B] 

   into the tensioner [C].

●

 Install the tensioner so that the stopper faces  

   upward.

ENGINE TOP END 5-13

Camshaft Chain Tensioner

●

 Tighten the tensioner mounting bolts [A].

   

Torque - Camshaft Chain Tensioner

    Mounting Bolts : 12N·m

●

 Install the spring and washer.

●

 Tighten the cap bolt [B].

    
   

Torque -  Camshaft Chain Tensioner Cap Bolt: 

   20N·m

5-14 ENGINE TOP END 

Camshaft/Timingchain

CAUTION

The crankshaft maybe tured while the 
crankshafts are removed.Aways pull the chain 
taut while turning the crankshaft.This avoids 
kinking the chain on the lower(crankshaft)
sprocket.A kinked chain could damage both 
the chain and the sprocket.

Camshaft Removal

●

 Remove:

   Cylinder Head Cover (see Cylinder Head Cover 
   Removal)

●

 Position the crankshaft as follows.

○

 Remove the upper [A] and lower [B] caps on the  

   clutch cover(right side cover).

○

 Using a wrench on the crankshaft rotation bolt, 

   turn the crankshaft clockwise until the 2/T mark 
   line [A] on the timing rotor is aligned with the 
   notch [B] in the edge of the upper hole [C] in the 
   clutch cover.

    

●

 Remove:

    Camshaft Chain Tensioner (see 
    Camshaft Chain Ten-sioner Removal) 
    Camshaft Cap Bolts [A] 
    Camshaft Caps [B] 
    Camshafts [C]