ATV500/ATV600/ATV650 

SERVICE MANUAL 

ENGINE 1

-------------------------------------------------CONTENTS-----------------------------------------------

ENGINE COMPONENTS REMOVABLE WITH ENGINE IN PLACE...2

ENGINE LEFT SIDE...2

ENGINE RIGHT SIDE....2

ENGINE CENTER...2

ENGINE DISASSEMBLY.3

ENGINE TOP SIDE.3

ENGINE BOTTOM SIDE6

ENGINE COMPONENTS INSPECTION AND SERVICING...15

CYLINDER HEAD COVER15

CYLINDER HEAD15

CAMSHAFT..26

CAM CHAIN TENSION ADJUSTER28

CYLINDER28

PISTON.29

CONROD / CRANKSHAFT31

CLUTCH32

MOVABLE DRIVE FACE AND DRIVEN FACE..34

DRIVE BELT41

OIL PUMP.41

TRANSFER..42

SHIFT FORK44

GEARSHIFT CAM...45

CRANKSHAFT..........46

DRIVE TRAIN (INBOARD SIDE)..47

SHIM ADJUSTMENT..56

CRANKCASE...60

DRIVE BELT COVER .66

GENERATOR COVER68

ENGINE REASSEMBLY..70

ENGINE BOTTOM SIDE70

ENGINE TOP SIDE.82

ENGINE 2

ENGINE COMPONENTS REMOVABLE WITH ENGINE IN PLACE

The parts listed below can be removed and installed without removing the engine from the frame.

Refer to the page listed in each section for removal and installation instructions.

ENGINE LEFTSIDE

PARTS

Water pump

Starter cup

Starter driven gear

Starter idle gear

Gearshift

Generator

Water pump drive/driven gear

REMOVAL

7

7

7

7

7

8

8

Installation

82

81

81

81

80

79

78

ENGINE RIGHT SIDE

PARTS

Clutch cover

Movable drive/driven face

Fixed drive face

Neutral switch

Clutch shoe

Cam chain

Oil pump

ENGINE CENTER

PARTS

Starter motor

Cam chain tension adjuster

Cylinder head cover

Camshaft

Cylinder head

Cylinder

Piston

Oil filter

Oil sump filter

Gearshift cam stopper

REMOVAL

9

9

10

10

11

11

12

Installation

77

76

76

75

74

74

73

REMOVAL

12

12

13

13

14

14

15

15

61

66

Installation

90

89

87

85

84

84

82

82

62

66

ENGINE 3

ENGINE DISASSEMBLY

ENGINE TOP SIDE

SPARK PLUG

• Remove the spark plug.

TOOL Spark plug wrench set

STARTER MOTOR

• Remove the starter motor.

CAM CHAIN TENSION ADJUSTER

• Remove the cap bolt

○

1

and insert the ─

○

screwdriver into the sloted end of the cam chain

tension adjuster and turn it clockwise to lock the

spring tension.

• Remove the cam chain tension adjuster.

ENGINE 4

○

A

• Remove the valve timing inspection plug ○1 .

• Turn the crankshaft and align the "TDC" line ○A on

the generator rotor with the index mark ○B on the

crankcase.

○

1

B

○

CYLINDER HEAD COVER

• Remove the valve inspection caps.

• Remove the cylinder head cover.

CAMSHAFT

• Flatten the lock washer.

• Remove the cam chain sprocket bolts and lock

washer.

• Remove the C-ring ○1 .

• Remove the camshaft and sprocket.

○

1

ENGINE 5

• Remove the cam chain tensioner by removing the

bolt.

CYLINDER HEAD

• Remove the cylinder head bolts and nuts.

• Remove the cylinder head bolts diagonally.

• Remove the cylinder head.

CYLINDER

• Remove the dowel pins and gasket.

• Remove the cam chain guide 1

○

○

1

ENGINE 6

• Remove the water hose/pipe.

• Remove the cylinder nuts.

• Remove the cylinder.

NOTE:

Be careful not to drop the dowel pins into the

crankcase.

• Remove the dowel pins and gasket.

PISTON

• Remove the piston by removing the piston pin

circlip ○1 .

NOTE:

Place a rag under the piston so as not to drop the

piiston pin circ-lip into the crankcase.

○

1

ENGINE BOTTOM SIDE

OIL FILTER

• Remove the oil filter with the special tool.

TOOL Oil filter wrench

TOOL

ENGINE 7

WATER PUMP

• Remove the water pump.

RECOIL HAND-OPERATED

• Remove the RECOIL HAND-OPERATED。

STARTUP DISK

• Remove the startup disk nut with tool.

• Remove the startup disk

STARTER CUP

• Remove the magneto cover.

ENGINE 8

STARTER DRIVEN GEAR/IDLE GEAR

• Remove the starter driven gear and idle gear.

GEARSHIFT

• Remove the gearshift shaft ○

gear ○2 .

1

○

2

and cam driven

○

1

GENERATOR

• Remove the generator rotor bolt with a offset

wrench.

• Remove the generator rotor with the special tool.

TOOL Rotor remover

• Remove the key ○1 .

• Remove the starter driven gear ○2 .

WATER PUMP DRIVE/DRIVEN GEAR

• Remove the water pump drive/driven gears by

removing the snap rings.

• Remove the pin ○3 and pin ○4 .

TOOL Snap ring pliers

ENGINE 9

CLUTCH OUTER COVER

• Remove the clutch outer cover.

MOVABLE DRIVE FACE

• Remove the movable drive face nut with the tool.

• Remove the movable driven face nut with the tool.

• Remove the movable drive face

• Remove the movable drive space .

ENGINE 10

• Remove the movable drive .

○

1

FIXED DRIVE FACE

• Remove the fixed drive face ○1 .

CLUTCH SPACER

• Remove the clutch spacer

• Remove the clutch housing case ○2 together with

the clutch housing/shaft ○3 .

•

NEUTRAL SWITCH

• Remove the neutral switch.

• Remove the springs and pins.

ENGINE 11

• Remove the breather pipe.

• Remove the output shaft housing.

• Remove the one way clutch ○1 .

○

1

CLUTCH SHOE

• Remove the clutch shoe nut with the special tool.

• Remove the clutch shoe.

CAUTION

The clutch shoe nut has left-hand threads.

TOOL Rotor holder

CAM CHAIN

• Remove the cam chain.

ENGINE 12

• Remove the oil pump drive gear bolt by engaging

a rag between the gears as shown.

• Remove the washer and oil pump drive gear.

1

○

○

2

• Remove the pin ○1 and spacer ○2 .

OIL PUMP

• Remove the oil pump driven gear by removing the

snap ring ○1 .

• Remove the pin ○2 and washer.

• Remove the oil pump.

TOOL Snap ring pliers

2

○

○

1

• Remove the left crankcase bolts.

• Remove the right crankcase bolts.

ENGINE 13

○

1

TRANSFER/DRIVE TRAIN/GEARSHIFT

• Remove the reverse idle gear ○1 .

• Remove the transfer input shaft 2

○

• Remove the gearshift related parts.

• Remove the transfer output shaft assembly ○3 .

○

2

○

3

• Remove the front output shaft

output shaft ○5 .

○

4

and rear

○

5

○

4

• Remove the C-ring.

ENGINE 14

○

1

BALANCER

• Remove the balancer shaft driven gear ○1 .

• Remove the key ○2 .

○

2

• Remove the balancer shaft with the special tool.

TOOL Sliding shaft

TOOL Attachment

• Remove the crankshaft with the special tool.

TOOL Crankcase separator

ENGINE 15

ENGINE COMPONENTS INSPECTION AND SERVICING

CYLINDER HEAD COVER

DISASSEMBLY

CAUTION

Be sure to identify each removed part as to its location, and

lay the parts out in groups designated as "Exhaust",

"Intake", so that each will be restored to the original

location during assembly.

○

B

○

A

• Remove the rocker arm shaft bolts A

○

• Remove the rocker arm shaft by using 6 mm bolts ○B .

CYLINDER HEAD COVER DISTORTION

After removing sealant from the fitting surface of the cylinder head

cover, place the cylinder head cover on a surface plate and check

for distortion with a thickness gauge.

DATA Cylinder head cover distortion

Service Limit: 0.05 mm (0.002 in)

TOOL Thickness gauge

If the distortion exceeds the limit, replace the cylinder head cover.

ROCKER ARM SHAFT O.D.

Measure diameter of rocker arm shaft.

DATA Rocker arm shaft O.D. (IN & EX)

Standard: 11.977 -11.995 mm

TOOL Micrometer(0-25mm)

○

A

ENGINE 16

ROCKER ARM I.D.

When checking the valve rocker arm, the inside

diameter of the valve rocker arm and wear of the

camshaft contacting surface should be checked.

DATA Rocker arm I.D.

Standard: 12.000 - 12.016mm

TOOL Dial calipers

REASSEMBLY

NOTE:

Intake rocker arm shaft ○A has the oil holes.

A

○

• Apply engine oil to the rocker arms and their shafts.

• Install the rocker arms and tighten the rocker arm

shaft bolts to the specified torque.

Rocker arm shaft bolt: 28 N m (2.8 kgf-m, 20.0 Ib-ft)

OIL

OIL

CYLINDER HEAD

DISASSEMBLY

• Remove the intake pipe.

• Remove the engine coolant temperature switch 1

○

and thermostat cover ○2 .

○

1

○

2

ENGINE 17

• Remove the thermostat.

• Compress the valve spring and remove the valve

cotters from the valve stem with the special tools.

TOOL Valve spring compressor

TOOL Attachment

TOOL Tweezers

• Remove the valve spring retainer and valve spring.

• Remove the valve from the other side.

• Remove the oil seal with long-nose pliers.

• Remove the valve spring seat.

NOTE:

Removal of valves completes ordinary disassembling

work. If valve guides have to be removed for

replacement after inspecting the related parts, carry

out the steps shown in the valve guide servicing.

ENGINE 18

CYLINDER HEAD DISTORTION

• Decarbonize the combustion chamber.

Check the gasket surface of the cylinder head for distortion using a

straightedge and thickness gauge. Take clearance readings at

several places. If any clearance reading exceeds the service limit,

replace the cylinder head with a new one.

TOOL Thickness gauge

DATA Cylinder head distortion

Service Limit: 0.05 mm (0.002 in)

VALVE STEM RUNOUT

Support the valve with "V" blocks, as shown, and check its runout

with a dial gauge.

The valve must be replaced if the runout exceeds the limit.

DATA

Valve stem runout

Service Limit: 0.05 mm (0.002 in)

TOOL Magnetic stand

TOOL Dial gauge(1/100 mm)

TOOL V-block

VALVE HEAD RADIAL RUNOUT

Place the dial gauge at right angles to the valve head face, and

measure the valve head radial runout.

If it exceeds limit, replace the valve.

DATA Valve head radial runout

Service Limit: 0.03 mm (0.001 in)

TOOL Magnetic stand

TOOL Dial gauge(1/100 mm)

TOOL V-block

VALVE FACE WEAR

Visually inspect each valve face for wear or damage. If any

abnormal wear is found, replace the respective valve with a new

one. Measure the valve head thickness ○T . If the valve head

thickness is not within the specified value, replace the value with a

new one。

TOOL Vernier calipers

DATA

Valve head thickness T

○

Service Limit: 0.5 mm (0.02 in)