Radiator Cap Relief Pressure

Standard: 112.3 ~ 141.7 kPa (1.15 ~ 1.45 kgf/cm², 16.3

~ 20.5 psi)

If the cap can not hold the specified pressure or if it holds too much pressure, replace it with a new one.

Radiator Filler Neck Inspection

• Remove the reserve tank (see Coolant Change in the Pe- riodic Maintenance chapter).

• Remove the radiator cap.

• Check the radiator filler neck for signs of damage.

• Check the condition of the top and bottom sealing seats

[A] in the filler neck. They must be smooth and clean for

the radiator cap to function properly.

 

 

Thermostat

Thermostat Removal

• Drain the coolant (see Coolant Change in the Periodic Maintenance chapter).

• Remove:

Left Center Fairing (see Center Fairing Removal in the

Frame chapter)

Thermostat Hosing Bolts [A] Thermostat Hosing [B]

 

 

• Pull the thermostat [A] out of the cylinder head.

 

 

Thermostat Installation

• Install the thermostat [A] in the cylinder head so that the air bleeder hole [B] is on top.

• Install a new O-ring into the housing and apply grease it.

• Tighten:

Torque - Thermostat Hosing Bolts: 9.8 N·m (1.0 kgf·m, 87 in·lb)

• Fill the radiator with coolant (see Coolant Change in the

Periodic Maintenance chapter).

 

Thermostat Inspection

• Remove the thermostat, and inspect the thermostat valve [A] at room temperature.

If the valve is open, replace the thermostat with a new one.

 

 

Thermostat

• To check valve opening temperature, suspend the ther- mostat [A] in a container of water and raise the tempera-

ture of the water.

○The thermostat must be completely submerged and must

not touch the container sides or bottom. Suspend an ac-

curate thermometer [B] in the water so that the heat sen- sitive portions [C] are located in almost the same depth. It must not touch the container, either.

If the measurement is out of the specified range, replace the thermostat with a new one.

Thermostat Valve Opening Temperature 80.5 ~ 83.5°C (177 ~ 182°F)

 

Hose and Pipes

Hose Installation

• Install the hoses and pipes, being careful to follow bend- ing direction. Avoid sharp bending, kinking, flattening or

twisting.

• Run the hoses (see Cable, Wire, and Hose Routing sec- tion in the Appendix chapter).

• Install the clamp [A] as near as possible to the hose end

to clear the raised rib of the fitting. This will prevent the

hoses from working loose.

○The clamp screws should be positioned correctly to pre-

vent 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 Con- dition Inspection in the Periodic Maintenance chapter.

 

 

Water Temperature Sensor

CAUTION

The water temperature sensor should never be al- lowed to fall on a hard surface. Such a shock to the water temperature sensor can damage it.

Water Temperature Sensor Removal/Installation

• Refer to the Water Temperature Sensor Removal/Instal- lation in the Fuel System (DFI) chapter.

Water Temperature Sensor [A]

 

Water Temperature Sensor Inspection

• Refer to the Water Temperature Sensor Inspection in the Electrical System chapter.

 

 

 

 

 

Engine Top End

Table of Contents

Exploded View........................................................................................................................ 5-3

Exhaust System...................................................................................................................... 5-8

Specifications......................................................................................................................... 5-10

Special Tools and Sealant...................................................................................................... 5-12

Clean Air System.................................................................................................................... 5-14

Air Suction Valve Removal................................................................................................ 5-14

Air Suction Valve Installation............................................................................................. 5-14

Air Suction Valve Inspection............................................................................................. 5-14 5

Air Switching Valve Removal............................................................................................ 5-14

Air Switching Valve Installation......................................................................................... 5-14

Air Switching Valve Operation Test................................................................................... 5-15

Air Switching Valve Unit Test............................................................................................ 5-15

Clean Air System Hose Inspection................................................................................... 5-15

Cylinder Head Cover.............................................................................................................. 5-16

Cylinder Head Cover Removal......................................................................................... 5-16

Cylinder Head Cover Installation...................................................................................... 5-16

Camshaft Chain Tensioner..................................................................................................... 5-18

Camshaft Chain Tensioner Removal................................................................................ 5-18

Camshaft Chain Tensioner Installation............................................................................. 5-18

Camshaft, Camshaft Chain.................................................................................................... 5-19

Camshaft Removal........................................................................................................... 5-19

Camshaft Installation........................................................................................................ 5-19

Camshaft and Sprocket Assembly.................................................................................... 5-22

Camshaft, Camshaft Cap Wear........................................................................................ 5-22

Camshaft Runout.............................................................................................................. 5-23

Cam Wear......................................................................................................................... 5-23

Camshaft Chain Removal................................................................................................. 5-23

Cylinder Head......................................................................................................................... 5-24

Cylinder Compression Measurement................................................................................ 5-24

Cylinder Head Removal.................................................................................................... 5-25

Cylinder Head Installation................................................................................................. 5-26

Cylinder Head Warp.......................................................................................................... 5-28

Valves..................................................................................................................................... 5-29

Valve Clearance Inspection.............................................................................................. 5-29

Valve Clearance Adjustment............................................................................................. 5-29

Valve Removal.................................................................................................................. 5-29

Valve Installation............................................................................................................... 5-29

Valve Guide Removal....................................................................................................... 5-29

Valve Guide Installation.................................................................................................... 5-30

Valve-to-Guide Clearance Measurement (Wobble Method)............................................. 5-30

Valve Seat Inspection....................................................................................................... 5-31

Valve Seat Repair............................................................................................................. 5-31

Cylinder, Pistons..................................................................................................................... 5-36

Cylinder Removal.............................................................................................................. 5-36

Cylinder Installation........................................................................................................... 5-36

Piston Removal................................................................................................................. 5-36

Piston Installation.............................................................................................................. 5-37

Cylinder Wear................................................................................................................... 5-38

Piston Wear...................................................................................................................... 5-38

Piston Ring, Piston Ring Groove Wear............................................................................. 5-39

 

 

 

Piston Ring Groove Width................................................................................................. 5-39

Piston Ring Thickness...................................................................................................... 5-39

Piston Ring End Gap........................................................................................................ 5-40

Throttle Body Holder............................................................................................................... 5-41

Throttle Body Holder Installation....................................................................................... 5-41 Muffler..................................................................................................................................... 5-42

Muffler Body Removal....................................................................................................... 5-42

Exhaust Pipe Removal...................................................................................................... 5-42 Muffler Body and Exhaust Pipe Installation...................................................................... 5-43

 

Dummy Page

 

 

 

 

 

No.	Fastener	Torque	Remarks
N·m	kgf·m	ft·lb
	Air Suction Valve Cover Bolts	9.8	1.0	87 in·lb
	Cylinder Head Cover Bolts	9.8	1.0	87 in·lb
	Camshaft Cap Bolts		1.2	106 in·lb	S
	Cylinder Head Bolts (M10 New Bolts)		5.5		MO, S
Cylinder Head Bolts (M10 Used Bolts)		5.0		MO, S
	Cylinder Head Bolts (M6)		1.2	106 in·lb	S
	Throttle Body Holder Bolts		1.2	106 in·lb
	Rear Camshaft Chain Guide Bolts		2.0		L
	Camshaft Chain Tensioner Mounting Bolts	9.8	1.0	87 in·lb
	Camshaft Chain Tensioner Cap Bolt		2.0
	Spark Plugs		1.5
	Camshaft Sprocket Bolts		1.5		L
	Baffle Plate Bolts	5.9	0.60	52 in·lb

L: Apply a non-permanent locking agent. M: Apply molybdenum disulfide grease.

MO: Apply molybdenum disulfide oil solution.

(mixture of the engine oil and molybdenum disulfide grease in a weight ratio 10: 1) R: Replacement Parts

S: Follow the specified tightening sequence. SS: Apply silicone sealant.

 

 

 

 

 

No.	Fastener	Torque	Remarks
N·m	kgf·m	ft·lb
	Cylinder Bolt (M8)	27.5	2.8		MO,S
	Cylinder Nut (M10)		5.0		MO,S
	Cylinder Bolts (M6)		1.2	106 in·lb	S
	Exhaust Pipe Manifold Holder Nuts		1.7
	Muffler Body Mounting Bolt (Front)		2.0
	Muffler Body Mounting Bolt (Rear)		2.0

7. "R" marked side faces up.

8. "RN" marked side faces up.

9. Hollow mark faces forward.

MO: Apply molybdenum disulfide oil solution.

(mixture of the engine oil and molybdenum disulfide grease in a weight ratio 10: 1) R: Replacement Parts

S: Follow the specified tightening sequence.

 

 

Exhaust System

Exhaust System EX650A6F/EX650B6F

Full: Full Power

H: Honeycomb Type Catalyst

Silencer [A] with Hole [B] for Oxygen Sensor [C]

 

 

Exhaust System

Manifold Mark Position [A]

 

Silencer Mark Position [A]

 

 

 

Specifications

Item	Standard	Service Limit
Camshafts Cam Height: Exhaust Inlet Camshaft Journal, Camshaft Cap Clearance Camshaft Journal Diameter Camshaft Bearing Inside Diameter Camshaft Runout	35.843 ~ 35.957 mm (1.4111 ~ 1.4156 in.)	35.74 mm (1.4071 in.)
36.543 ~ 36.657 mm (1.4387 ~ 1.4432 in.)	36.44 mm (1.4346 in.)
0.028 ~ 0.071 mm (0.0011 ~ 0.0028 in.)	0.16 mm (0.0063 in.)
23.950 ~ 23.972 mm	23.92 mm (0.942 in.)
(0.9429 ~ 0.9438 in.)
24.000 ~ 24.021 mm	24.08 mm (0.948 in.)
(0.9449 ~ 0.9457 in.)
TIR 0.02 mm (0.0008 in.) or less	TIR 0.1 mm (0.004 in.)
Cylinder Head
Cylinder Compression	(Usable Range)
	961 ~ 1 471 kPa (9.8 ~ 15.0 kgf/cm², 139	– – –
	~ 213 psi) at 400 r/min (rpm)
Cylinder Head Warp	– – –	0.05 mm (0.002 in.)
Valves Valve Clearance: Exhaust Inlet Valve Head Thickness: Exhaust Inlet Valve Stem Bend Valve Stem Diameter: Exhaust Inlet Valve Guide Inside Diameter: Exhaust Inlet Valve/Valve Guide Clearance (Wobble Method): Exhaust Inlet Valve Seat Cutting Angle Valve Seating Surface: Width: Exhaust Inlet Outside Diameter: Exhaust Inlet	0.22 ~ 0.31 mm (0.0087 ~ 0.0122 in.)	– – –
0.15 ~ 0.21 mm (0.0059 ~ 0.0083 in.)	– – –
0.8 mm (0.031 in.)	0.5 mm (0.020 in.)
0.5 mm (0.020 in.)	0.25 mm (0.0098 in.)
TIR 0.01 mm (0.0004 in.) or less	TIR 0.05 mm
	(0.002 in.)
4.455 ~ 4.470 mm (0.1754 ~ 0.1760 in.)	4.44 mm (0.175 in.)
4.475 ~ 4.490 mm (0.1762 ~ 0.1768 in.)	4.46 mm (0.176 in.)
4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in.)	4.58 mm (0.180 in.)
4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in.)	4.58 mm (0.180 in.)
0.07 ~ 0.14 mm (0.0028 ~ 0.0055 in.)	0.27 mm (0.0106 in.)
0.02 ~ 0.08 mm (0.0008 ~ 0.0032 in.)	0.22 mm (0.0087 in.)
32°, 45°, 55°, 60°	– – –
0.5 ~ 1.0 mm (0.020 ~ 0.039 in.)	– – –
0.5 ~ 1.0 mm (0.020 ~ 0.039 in.)	– – –
27.6 ~ 27.8 mm (1.087 ~ 1.094 in.)	– – –
32.6 ~ 32.8 mm (1.283 ~ 1.291 in.)	– – –

 

Specifications

Item	Standard	Service Limit
Valve Spring Free Length: Exhaust Inlet	41.91 mm (1.650 in.) 41.91 mm (1.650 in.)	40.3 mm (1.587 in.) 40.3 mm (1.587 in.)
Cylinder, Pistons Cylinder Inside Diameter Piston Diameter Piston/Cylinder Clearance Piston Ring/Groove Clearance: Top Second Piston Ring Groove Width: Top Second Piston Ring Thickness: Top Second Piston Ring End Gap: Top Second	82.994 ~ 83.006 mm	83.10 mm (3.2716 in.)
(3.2675 ~ 3.2679 in.)
82.969 ~ 82.984 mm	82.82 mm (3.2606 in.)
(3.2665 ~ 3.2671 in.)
0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in.)	– – –
0.03 ~ 0.07 mm (0.0012 ~ 0.0028 in.)	0.17 mm (0.0067 in.)
0.02 ~ 0.06 mm (0.0008 ~ 0.0024 in.)	0.16 mm (0.0063 in.)
0.92 ~ 0.94 mm (0.0362 ~ 0.0370 in.)	1.02 mm (0.040 in.)
1.01 ~ 1.03 mm (0.0398 ~ 0.0406 in.)	1.11 mm (0.044 in.)
0.87 ~ 0.89 mm (0.0342 ~ 0.0350 in.)	0.80 mm (0.031 in.)
0.97 ~ 0.99 mm (0.0382 ~ 0.0390 in.)	0.90 mm (0.035 in.)
0.25 ~ 0.40 mm (0.0098 ~ 0.0157 in.)	0.7 mm (0.028 in.)
0.40 ~ 0.55 mm (0.0157 ~ 0.0217 in.)	0.8 mm (0.031 in.)

 

Special Tools and Sealant

Compression Gauge, 20 kgf/cm²: 57001-221

Valve Seat Cutter, 60° - 30:

57001-1123

Valve Spring Compressor Assembly: 57001-241