CFMoto motorcycle CF650NK. Service Manual - part 21

ENGINE TOP END 5-31

Cylinder/Pistons

Cylinder Wear

●

 

Since there is a difference in cylinder wear 

    in different directions, take a side-to-side and a 
    front-to-back measurement at each of the two 
    locations (total of four measure- ments) shown 
    in the 

fi

 gure.

   10mm [A]
    60mm [B]
  

  Cylinder Inside Diameter

    Standard:83.00mm~83.02mm
    Service limit:83.10mm

Piston wear

●

 Measure the outside diameter [A] of each piston   

  10mm [B] up from the bottom of the piston at a 
   right angle to the direction of the piston pin.
   If themeasurement is under service limit, replace 
    the piston.

    

Piston diameter

    Standard:82.975mm~82.995mm
    Service limit : 82.90mm

Piston Ring, Piston Ring Groove Wear

●

 Check for uneven groove wear by inspecting the  

   ring seat.

5-32 ENGINE TOP END 

Cylinder/Piston

○

 The rings should fit perfectly parallel to groove 

   surfaces. If not, replace the piston and all the 
    piston rings.

●

 With the piston rings in their grooves, make 

    several measurements with a thickness gauge 
    [A] to determine piston ring/groove clearance.

   

 Piston Ring/Groove  Clearance

    Top
    Standard: 0.04mm~0.075mm
    Service limit : 0.17mm
    Second
    Standard:  0.02mm~ 0.06mm
    Service limit: 0.16mm

Piston Ring Groove Width

●

 Measure the piston ring groove width.

   Use a vernier caliper at several points around the 
   piston.
     
 

  Piston Ring Groove Width

   Top [A]
   Standard:  0.92mm~0.94mm
   Service limit: 1.02mm
   Second [B]
   Standard: 1.01mm ~1.03mm
   Service limit: 1.11mm

ENGINE TOP END 5-33

Cylinder/Piston

●

 Measure the piston ring thickness: 

○

 Use the micrometer to measure at several points 

   around the ring.
    Piston Ring Thickness
    Top ring [A]
    Standard:  0.865mm ~0.88mm
    Service limit: 0.80mm
    Second ring [B]
    Standard:  0.97mm~0.99mm
    Service limit: 0.90mm

  If any of the measurements is less than the 
  service limit on either of the rings, replace all the 
   rings.

                                   

NOTE

○

 

When using new rings in a used piston, check for 

  un-even groove wear. The rings should fit 
  perfectly parallel to the groove sides. If not, 
   replace the piston.

Piston Ring End Gap

●

 Place the piston ring [A] inside the cylinder, using 

   the piston to locate the ring squarely in place. Set 
  it close to the bottom of the cylinder, where 
   cylinder wear is low.

●

 Measure the gap [B] between the ends of the 

   ring with a thickness gauge.

   Piston Ring End Gap 
   Top
      Standard:  0.15mm~ 0.30mm
      Service limit: 0.60mm
    Second
      Standard: 0.30mm~ 0.45mm
      Service limit : 0.70mm

  If the end gap of either ring is greater than the 
   service limit, replace all the rings.

5-34 ENGINE TOP END 

Intake Manifold

Intake manifold installation

●

 

Be sure to install the O-rings [A].

●

 

Install the clamps [B] as shown and so 

   that their projections 

fi

 t [C] on the holes 

    of intake manifold.
   Be sure that the clamp bolt heads [D] 
    face outwards.

●

 Tighten screw [E].

  Torque - Intake manifold screw: 
   12N·m

CLUTCH 6-1

Clutch

Table of Contents

Exploded View.............................................................................................................................

6-2

Speci

fi

 cations..............................................................................................................................

6-4

Special Tool and Sealant..............................................................................................................

6-5

Clutch Cover................................................................................................................................

6-6

Clutch Cover Removal............................................................................................................

6-6

Clutch Cover Installation.........................................................................................................

6-7

Release Shaft Removal...........................................................................................................

6-8

Release Shaft Installation........................................................................................................

6-8

Clutch Cover Disassembly......................................................................................................

6-9

Clutch Cover Assembly...........................................................................................................

6-10

Clutch..........................................................................................................................................

6-11

Clutch Removal.......................................................................................................................

6-11

Clutch Installation....................................................................................................................

6-12

Clutch Plate, Wear, Damage Inspection..................................................................................

6-16

Clutch Plate Warp Inspection..................................................................................................

6-16

Clutch Spring Free Length Measurement................................................................................

6-16

Clutch Housing Finger Inspection...........................................................................................

6-17

Clutch Housing Spline Inspection............................................................................................

6-17

6-2 CLUTCH

Exploded View

CLUTCH 6-3

Exploded View

NO

Fastener

Torque

Remarks

N·m

kgf·m

ft·lb

1

Upper Cap on Clutch Cover

–

–

–

Hand-tighten

2

Lower Cap on Clutch Cover

(25)

(2.5)

(18)

Hand-tighten

3

Oil Filler Plug

–

–

–

Hand-tighten

4

Clutch Cover Mounting Bolts

12

1.2

106 in·lb

5

Clutch Spring Bolts

10

1.0

87 in·lb

6

Clutch Hub Nut

132

13.5

98

L,R

7

Oil Pump Sprocket Bolt

12

1.2

106 in·lb

L,Lh

8

Clutch Lever Clamp Bolts

7.8

0.80

69 in·lb

S

9

Oil Pump Chain Guide Bolts

10

1.0

87 in·lb

L

10

Clutch Cable Holder Bolts

10

1.0

87 in·lb

L/SS

11

Clutch Cable Clamp Bolt

10

1.0

87 in·lb

L

CL:   Apply cable lubricant. 

EO:   Apply engine oil.

G:  

Apply grease.

HG:   Apply high-temperature grease.

L:  

Apply a non-permanent locking agent.

Lh:   Left-hand threads

M:  

Apply molybdenum disul

fi

 de grease. 

R:  

Replacement Parts

S:  

Follow the speci

fi

 ed tightening sequence.

W:  

Apply cylindrical surface grease.

SS:   Apply Silicone sealant

6-4 CLUTCH

Specifi cations

Item

          Standard

Service Limit

Clutch Lever Free Play

2~3mm(0.08~0.12in.)

–––

Clutch
Friction Plate Thickness            
Friction Plate Warp
Steel Plate Warp
Clutch Spring Free Length

2.95~3.05mm (0.116~0.120in.)   
0.15mm (0.16in.) or less
0.2mm (0.008in.) or less    
33.6mm (1.32in.)

2.83mm(0.110in.) 
0.3mm(0.012in.) 
0.3mm(0.012in.)        
32.6mm (1.28in.) 

CLUTCH 6-5

Special Tool and Sealant

Clutch Holder                                                  Silicone Sealant

6-6 CLUTCH

Clutch Cover

Clutch Cover Removal

●

 

Removal:

    Engine Oil (Drain, see Engine Oil Change in the  
    Periodic Maintenance chapter)
    Right Frame Cover (see Frame Cover Removal 
    in the  Frame chapter) 
    Clutch Cable Lower End [A] 
    Clutch Cover Mounting Bolts [B]

●

 Turn the release lever [A] toward the rear 

    as shown, and remove the clutch 
    cover [B] About 90

o 

[C].

CLUTCH 6-7

Clutch Cover

Clutch Cover Installation

●

 Apply silicone sealant to the area [A] where the 

  mating surface of the crankcase touches the 
   clutch cover gasket and to the crankshaft sensor 
   lead grommet [B].

●

 Be sure that the dowel pins [C] are in position.

●

 Replace the clutch cover gasket [D] with a new 

    one.

●

 Tighten the clutch cover mounting bolts.

  

 Torque - Clutch Cover Mounting Bolts: 12 N·m

6-8 CLUTCH

Clutch Cover

Release Shaft Removal    

●

 

Remove the clutch cover (see Clutch Cover 

     Removal).

●

 

Pull the lever and shaft assembly straight out of 

    the clutch cover

Release Shaft Installation

●

 

Apply high-temperature grease to the oil seal lips 

    on the  upper ridge of the clutch cover.

●

 

Apply engine oil to the needle bearings in the 

    hole of the  clutch cover.

●

 

Apply molybdenum disulfide grease to the 

    pusher-holding portion [A] on the release shaft.

●

 

Install the washer [B] and spring [C].

●

 

Insert the release shaft straight into the upper 

    hole hole of theclutch cover.                       

CAUTION

When inserting the release shaft, be careful 
not to remove the spring of the oil seal.

 

●

 

Fit the spring [A] as shown.

    Release Shaft [B]
    Clutch Cover [C]

CLUTCH 6-9

Clutch Cover

Clutch Cover Disassembly

●

 Remove:

   Oil Seal [A]
   Needle Bearings [B]

●

 Remove the oil level gauge [A].

6-10 CLUTCH

Clutch Cover 

Clutch Cover Assembly

●

 

Replace the needle bearings and oil seal 

     with new ones.

                              

NOTE

○

   

Install the needle bearings so that the 

    manufacture's mark face out.

●

 

Install the needle bearings [A] and oil seal [B] 

     position as shown.

●

 

Press  [C] the bearing so that the bearing 

     surface [D] is 

fl

 ush with the housing end of clutch 

     cover [E].

●

 

Apply grease to the rubber of the oil gauge [A] 

     and press [B] it so that the ring [C] face  outside.

CLUTCH 6-11

Clutch

Clutch Removal

●

 Remove:

  Engine Oil (Drain, see Engine Oil Change in the 
   Periodic Maintenance chapter) Clutch Cover (see  
   Clutch Cover Removal) Clutch Spring Bolts [A]
   Clutch Springs
  Clutch Spring Plate [B] (with thrust bearing and   
   pusher [C])

●

 Remove:

   Friction Plates, Steel Plates
   Clutch Hub Nut [A]
  Holding the clutch hub [B], remove the nut and   
   washer.

  

 Special Tool -  Clutch Holder [C]

●

 Remove: 

   Clutch Hub Spacer

6-12 CLUTCH

Clutch

●

 Remove the oil pump sprocket bolt [A].        

                                  

NOTE

○

 

The oil pump sprocket bolt has a left-hand  

   threads.

●

 Using the hole [B], pull out the sleeve [C].

●

 Remove the following as a set.

   Clutch Housing [D]
   Oil Pump Chain [E]
   Oil Pump Sprocket [F]

●

 Unscrew the bolts [A] and remove the oil pump 

   chain guide [B].

Clutch Installation

●

 Apply a non-permanent locking agent to the oil 

   pump chain guide bolts and tighten them.
   Torque - Oil Pump Chain Guide Bolts: 10

N·m

●

 Put the oil pump chain [A] on the clutch housing 

   gear [B] and the oil pump sprocket [C].