• Remove:
Middle Front Engine Mounting Bolt [A] (Both Sides)
• Remove the cylinder.
NOTE

○If it is hard to remove it, tap lightly using a plastic-faced
mallet.

Cylinder Installation
NOTE

○If a new cylinder is used, use new piston ring.
the cylinder gasket [A] with a new one.
• Replace
Install
the
dowel pins [B] and new cylinder gasket.
• Apply molybdenum
disulfide oil solution to the cylinder
• bore.

piston ring openings must be positioned as shown.
• The
The openings of the oil ring steel rails must be about 30
 40° of angle from the opening of the top ring.
Top Ring [A]
Second Ring [B]
Upper Oil Ring Steel Rail [C]
Oil Ring Expander [D]
Lower Oil Ring Steel Rail [E]
Dent [F]
30  40° [G]

ENGINE TOP END 5-37
Cylinder, Pistons
the crankshaft at #2, 3 piston TDC.
• Position
Prepare
two
head bolts with their head cut.
•○Install the twoauxiliary
cylinder head bolts [A] diagonally in the
crankcase.
Install the cylinder block [B].
Pistons [C]
○First insert the #2, 3 pistons, and then rotate the crankshaft at 90° angle, and insert the #1, 4 pistons.
○Insert the piston rings with your thumbs or the flat tip
screwdriver.
Wipe off any excess oil.
Install the removed parts (see appropriate chapters).

•

•
•

Piston Removal

the cylinder (see Cylinder Removal).
• Remove
a clean cloth under the pistons and remove the pis• Place
ton pin snap ring [A] from the outside of each piston.

the piston pin puller assembly [A], remove the pis• Using
ton pins.
Special Tool - Piston Pin Puller Assembly: 57001-910

• Remove the pistons.

spread the ring opening with your thumbs and
• Carefully
then push up on the opposite side of the ring [A] to remove

•

it.
Remove the 3-piece oil ring with your thumbs in the same
manner.

5-38 ENGINE TOP END
Cylinder, Pistons
Piston Installation
NOTE

○If a new piston is used, use new piston ring.
molybdenum disulfide oil solution to the oil ring ex• Apply
pander, and install the oil ring expander [A] in the bottom
piston ring groove so the ends [B] not butt together.
Apply molybdenum disulfide oil solution to the oil ring steel
rails, and install the oil ring steel rails, one above the expander and one below it.
○Spread the rail with your thumbs, but only enough to fit
the rail over the piston.
○Release the rail into the bottom piston ring groove.

•

NOTE

○The oil ring rails have no “top” or “bottom.”
molybdenum disulfide oil solution to the piston
• Apply
rings.

NOTE

○Do not mix up the top and second ring.
the top ring [A] so that the “1R” mark [B] faces up.
• Install
Install
the
second ring [C] so that the “2R” mark [D] faces
• up.

the piston with its dent mark facing forward.
• Install
Apply
molybdenum
• and piston journals.disulfide oil solution to the piston pins
a new piston pin snap ring into the side of the piston
• Fit
so that the ring opening [A] does not coincide with the slit
[B] of the piston pin hole.
○When installing the piston pin snap ring, compress it only
enough to install it and no more.

NOTICE
Do not reuse snap rings, as removal weakens and
deforms them. They could fall out and score the
cylinder wall.

• Install the cylinder (see Cylinder Installation).
Cylinder Wear Inspection

there is a difference in cylinder wear in different di• Since
rections, take a side-to-side and a front-to-back measurement at each of the two locations (total of four measurements) as shown.
If any of the cylinder inside diameter measurements exceeds the service limit, replace the cylinder.
10 mm (0.39 in.) [A]
60 mm (2.36 in.) [B]
Cylinder Inside Diameter
Standard:
73.394  74.406 mm (2.8895  2.8900 in.)
Service Limit: 73.49 mm (2.893 in.)

ENGINE TOP END 5-39
Cylinder, Pistons
Piston Wear Inspection

the outside diameter [A] of each piston 11 mm
• Measure
(0.43 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the piston.
Piston Diameter
Standard:
73.374  73.384 mm (2.8887  2.8891 in.)
Service Limit: 73.22 mm (2.883 in.)

Piston Ring, Piston Ring Groove Wear Inspection

for uneven groove wear by inspecting the ring seat• Check
ing.

•

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
Standard:
Top

0.035  0.070 mm (0.00138  0.00276
in.)

Second

0.020  0.055 mm (0.00079  0.00217
in.)

Service Limit:
Top

0.17 mm (0.0067 in.)

Second

0.16 mm (0.0063 in.)

Piston Ring Groove Width Inspection

the piston ring groove width.
•○Measure
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A]

0.82  0.84 mm (0.0323  0.0331 in.)

Second [B]

0.81  0.83 mm (0.0319  0.0327 in.)

Service Limit:
Top

0.92 mm (0.0362 in.)

Second

0.91 mm (0.0358 in.)

If the width of any of the two grooves are wider than the
service limit at any point, replace the piston.

5-40 ENGINE TOP END
Cylinder, Pistons
Piston Ring Thickness Inspection

the piston ring thickness.
•○Measure
Use the micrometer to measure at several points around
the ring.
Piston Ring Thickness
Standard:
Top [A]

0.770  0.785 mm (0.0303  0.0309 in.)

Second [B]

0.775  0.790 mm (0.0305  0.0311 in.)

Service Limit:
Top

0.70 mm (0.028 in.)

Second

0.71 mm (0.028 in.)

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

Piston Ring End Gap Inspection

the piston ring [A] inside the cylinder, using the pis• Place
ton 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
Standard:
Top

0.15  0.25 mm (0.0059  0.0098 in.)

Second

0.30  0.40 mm (0.0118  0.0157 in.)

Service Limit:
Top

0.6 mm (0.02 in.)

Second

0.7 mm (0.03 in.)

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

ENGINE TOP END 5-41
Throttle Body Assy Holder
Throttle Body Assy Holder Removal

• Remove:
Throttle Body Assy (see Throttle Body Assy Removal in
the Fuel System (DFI) chapter)
Clamps [A]
Throttle Body Assy Holder Bolts [B]
Throttle Body Assy Holders [C]

Throttle Body Assy Holder Installation

the O-rings [A] with new ones.
• Replace
liquid gasket to any three positions [B] of the O
• Apply
-rings to prevent it from coming off, and install them.
Sealant - Liquid Gasket, TB1211F: 92104-0004

• Install:
Throttle Body Assy Holders
the throttle body assy holder bolts following the
• Tighten
specified tightening sequence [1  3].
Torque - Throttle Body Assy Holder Bolts: 12 N·m (1.2
kgf·m, 106 in·lb)

• Wipe off any excess liquid gasket.
the hole of all clamps [A] to the projection [B] of all
• Fit
holders [C].

○Be sure that the clamp bolt heads [D] face as shown.

• Install:
Throttle Body Assy (see Throttle Body Assy Installation
in the Fuel System (DFI) chapter)

5-42 ENGINE TOP END
Muffler
WARNING
The exhaust pipe or muffler body can become extremely hot during normal operation and cause severe burns. Do not remove the exhaust pipe or muffler body while it is hot.

Muffler Body Removal

• Remove:
Bolts [A] with Collars
Muffler Cover [B]

the muffler body clamp bolt [A].
• Loosen
Remove:
• Muffler Body Mounting Bolt [B], Washer and Nut
Muffler Body [C]

ENGINE TOP END 5-43
Muffler
This page intentionally left blank.

5-44 ENGINE TOP END
Muffler
Muffler Body Installation

the muffler body gasket [A] with a new one.
• Replace
the muffler body gasket until it is bottomed so that
• Install
the inside chamfer side face front [B].
the muffler body clamp [C] so that the projection [D]
• Install
fits into the clamp slit.
the muffler body until it stop at the bottom surface
• Install
of the exhaust pipe.
the muffler body mounting nut [E] with a new one.
• Replace
Install
the
• Tighten: muffler body mounting bolt [F] and nut.
•
Torque - Muffler Body Mounting Bolt: 34 N·m (3.5 kgf·m, 25
ft·lb)

the muffler body clamp outward until it stops at the
• Turn
slit ends.
• Tighten the muffler body clamp bolt [G].

ENGINE TOP END 5-45
Muffler

warm up the engine, wait until the engine
• Thoroughly
cools down, retighten all the bolts and nuts.
that the pads [A] are in place on the muffler body
• Check
cover.

the dampers [A], collars [B].
• Install
Tighten
muffler cover bolt.
• L = 27 the
mm (1.06 in.) [C]
L = 14 mm (0.55 in.) [D]

5-46 ENGINE TOP END
Muffler
Exhaust Pipe Removal

• Remove:
Radiator (see Radiator and Radiator Fan Removal in the
Cooling System)
Muffler Body (see Muffler Body Removal)
Oxygen Sensor (see Oxygen Sensor Removal in the
Electrical System chapter)
Support the premuffler chamber with the suitable stand
[A].
Remove the premuffler chamber mounting bolt [B].

•
•
• Remove:
Exhaust Pipe Holder Nuts [A]

Exhaust Pipe (Premuffler Chamber) [B]

Exhaust Pipe Installation

the exhaust pipe gaskets [A] with new ones.
• Replace
grease to the exhaust pipe gaskets and install them.
• Apply
Install
pipe.
• Tightenthetheexhaust
premuffler
chamber mounting bolt [B].
•
Torque - Premuffler Chamber Mounting Bolt: 34 N·m (3.5
kgf·m, 25 ft·lb)

the exhaust pipe holder nuts.
• Tighten
the removed parts (see appropriate chapters).
• Install
Thoroughly
up the engine, wait until the engine
• cools down, warm
retighten all the bolts and nuts.

CLUTCH 6-1

Clutch
Table of Contents
Exploded View........................................................................................................................
Specifications .........................................................................................................................
Special Tool and Sealant ........................................................................................................
Clutch Lever and Cable ..........................................................................................................
Clutch Lever Free Play Inspection ....................................................................................
Clutch Lever Free Play Adjustment ..................................................................................
Clutch Cable Removal ......................................................................................................
Clutch Cable Installation ...................................................................................................
Clutch Cable Lubrication...................................................................................................
Clutch Lever Assembly Installation ...................................................................................
Clutch Lever and Cable ..........................................................................................................
Clutch Lever Removal.......................................................................................................
Clutch Lever Installation....................................................................................................
Clutch Lever Position Adjustment .....................................................................................
Clutch Cover...........................................................................................................................
Clutch Cover Removal ......................................................................................................
Clutch Cover Installation ...................................................................................................
Release Shaft Removal ....................................................................................................
Release Shaft Installation .................................................................................................
Clutch Cover Disassembly................................................................................................
Clutch Cover Assembly.....................................................................................................
Clutch .....................................................................................................................................
Clutch Removal.................................................................................................................
Clutch Installation..............................................................................................................
Clutch Plate Assembly Length Inspection.........................................................................
Clutch Plate Assembly Length Adjustment .......................................................................
Clutch Plate, Wear, Damage Inspection ...........................................................................
Clutch Plate Warp Inspection............................................................................................
Clutch Housing Finger Inspection .....................................................................................
Clutch Housing Spline Inspection .....................................................................................
Clutch Pressure Plate and Clutch Hub Inspection ............................................................
Clutch Spring Inspection ...................................................................................................

6-2
6-4
6-5
6-6
6-6
6-6
6-6
6-6
6-6
6-6
6-7
6-7
6-7
6-8
6-9
6-9
6-9
6-9
6-10
6-10
6-11
6-12
6-12
6-13
6-16
6-16
6-17
6-17
6-17
6-17
6-18
6-18

6

6-2 CLUTCH
Exploded View

CLUTCH 6-3
Exploded View
No.

Fastener

1
2
3

Clutch Spring Bolts
Clutch Hub Nut
Clutch Lever Clamp Bolts

4

Oil Filler Plug

5
6

Clutch Cover Plate Bolt
Clutch Cover Bolts

N·m
8.8
135
11
Hand
-tighten
4.0
12

CL: Apply cable lubricant.
EO: Apply engine oil.
G: Apply grease.
L: Apply a non-permanent locking agent.
M: Apply molybdenum disulfide grease.
R: Replacement Parts
S: Follow the specified tightening sequence.
WL: Apply soap and water solution or rubber lubricant.

Torque
kgf·m
0.90
13.8
1.1

ft·lb
78 in·lb
100
97 in·lb

–

–

0.41
1.2

35 in·lb
106 in·lb

Remarks

R
S

L
S

6-4 CLUTCH
Specifications
Item
Clutch Lever and Cable
Clutch Lever Position
Clutch Lever Free Play
Clutch
Clutch Plate Assembly Length
Friction Plate Thickness
Friction and Steel Plate Warp

Standard