Page 129 of 2493

SEM174D
9. Remove the following parts:
+RH and LH front tires
+Splash covers
+RH and LH brake caliper assemblies
Refer to BR-27, ªFRONT DISC BRAKEº.
Brake hose does not need to be disconnected from brake
caliper assembly. Never depress brake pedal.
+RH & LH drive shaft. Refer to AX-10, ªDrive Shaftº.
When removing drive shaft, be careful not to damage tran-
saxle side grease seal.
SEM109G
+Disconnect control rod and support rod from transaxle. (M/T
models.)
Refer to MT-29, ªTRANSAXLE GEAR CONTROLº.
+Disconnect control cable from transaxle. (A/T models.)
Refer to AT-346, ªRemovalº.
SEM108G
+Center member
+Front exhaust tube
+Stabilizer bar
+Cooling fan
+Radiator
+Disconnect wires, harness, pipes, hoses and so on.
10. Lift up engine slightly and disconnect or remove all engine
mountings.
When lifting engine, be sure to clear surrounding parts. Use
special care near brake tubes and brake master cylinder.
11. Remove engine with transaxle as shown.
SEM420D
INSTALLATIONNJEM0022S02+Install in reverse order of removal.
ENGINE ASSEMBLYQG
Removal and Installation (Cont'd)
EM-51
Page 130 of 2493
ComponentsNJEM0023
YEM022
1. Oil level gauge guide
2. Cylinder block
3. Rear oil seal retainer
4. Rear oil seal
5. Rear plate
6. Flywheel
7. Drain plug
8. Buffle plate
9. Top ring10. 2nd ring
11. Oil ring
12. Piston
13. Snap ring
14. Piston pin
15. Connecting rod
16. Connecting rod bearing
17. Connecting rod cap
18. Key19. Main bearing
20. Thrust bearing
21. Crankshaft
22. Main bearing cap
23. Knock sensor
24. Crankshaft position sensor (POS)
25. Rear lower plate
26. Drive plate
27. Signal plate
CYLINDER BLOCKQG
Components
EM-52
Page 131 of 2493

Removal and InstallationNJEM0024CAUTION:
+When installing sliding parts such as bearings and
pistons, apply engine oil on the sliding surfaces.
+Place removed parts, such as bearings and bearing caps,
in their proper order and direction.
+When installing connecting rod nuts and main bearing cap
bolts, apply new engine oil to threads and seating sur-
faces.
+Do not allow any magnetic materials to contact the signal
plate teeth of flywheel or drive plate, and rear plate.
+Remove the crankshaft position sensor (POS).
+Be careful not to damage sensor edges and single plate
teeth.
SEM927F
DisassemblyNJEM0025PISTON AND CRANKSHAFTNJEM0025S011. Place engine on a work stand.
2. Drain coolant and oil.
3. Remove timing chain.
Refer to EM-23.
SEM877B
4. Remove pistons with connecting rod.
+When disassembling piston and connecting rod, remove snap
ring first. Then heat piston to 60 to 70ÉC (140 to 158ÉF) or use
piston pin press stand at room temperature.
CAUTION:
+When piston rings are not replaced, make sure that piston
rings are mounted in their original positions.
+When replacing piston rings, if there is no punch mark,
install with either side up.
SEM165DB
5. Loosen main bearing caps in numerical order as shown in fig-
ure.
6. Remove bearing caps, main bearings and crankshaft.
+Before removing bearing caps, measure crankshaft end
play. Refer to EM-61.
+Bolts should be loosened in two or three steps.
CYLINDER BLOCKQG
Removal and Installation
EM-53
Page 132 of 2493

SEM928F
7. Remove signal plate from crankshaft.
AEM023
InspectionNJEM0026PISTON AND PISTON PIN CLEARANCENJEM0026S011. Measure inner diameter of piston pin hole ªdpº.
Standard diameter ªdpº:
QG18DE
18.993 - 19.005 mm (0.7478 - 0.7482 in)
QG15DE
18.987 - 18.999 mm (0.7475 - 0.7480 in)
AEM024
2. Measure outer diameter of piston pin ªDpº.
Standard diameter ªDpº:
18.989 - 19.001 mm (0.7476 - 0.7481 in)
3. Calculate piston pin clearance.
QG18DE
Dp þ dp: 0.002 - 0.006 mm (0.0001 - 0.0002 in)
QG15DE
Dp þ dp: þ0.004 to 0 mm (þ0.0002 to 0 in)
If it exceeds the above value, replace piston assembly with pin.
SEM024AA
PISTON RING SIDE CLEARANCENJEM0026S02Side clearance:
Refer to SDS, EM-73.
Max. limit of side clearance:
Refer to SDS, EM-73.
If out of specification, replace piston and/or piston ring assembly.
AEM096
PISTON RING END GAPNJEM0026S03End gap:
Refer to SDS, EM-73.
Max. limit of end gap:
Refer to SDS, EM-73.
If out of specification, replace piston ring. If gap exceeds maximum
limit with a new ring, rebore cylinder and use oversized piston and
piston rings.
Refer to SDS, EM-73.
+When replacing the piston, check the cylinder bore surface for
CYLINDER BLOCKQG
Disassembly (Cont'd)
EM-54
Page 133 of 2493

scratches or seizure. If scratches or seizure is found, hone or
replace the cylinder block.
SEM150B
CONNECTING ROD BEND AND TORSIONNJEM0026S04Bend:
Limit 0.15 mm (0.0059 in)
per 100 mm (3.94 in) length
Torsion:
Limit 0.3 mm (0.012 in)
per 100 mm (3.94 in) length
If it exceeds the limit, replace connecting rod assembly.
SEM003F
SEM486C
CYLINDER BLOCK DISTORTION AND WEARNJEM0026S05Clean upper surface of cylinder block.
Use a reliable straightedge and feeler gauge to check the flatness
of cylinder block surface. Check along six positions shown in fig-
ure.
Block surface flatness:
Standard Less than 0.03 mm (0.0012 in)
Limit 0.10 mm (0.004 in)
If out of specification, resurface it.
The limit for cylinder block resurfacing is determined by the amount
of cylinder head resurfacing.
SEM102F
Amount of cylinder head resurfacing is ªAº.
Amount of cylinder block resurfacing is ªBº.
The maximum limit is as follows:
A + B = 0.2 mm (0.008 in)
Nominal cylinder block height
from crankshaft center:
213.95 - 214.05 mm (8.4232 - 8.4271 in)
If necessary, replace cylinder block.
CYLINDER BLOCKQG
Inspection (Cont'd)
EM-55
Page 134 of 2493

SEM166D
SEM929F
PISTON-TO-BORE CLEARANCENJEM0026S061. Using a bore gauge, measure cylinder bore for wear, out-of-
round and taper.
Standard inner diameter:
Refer to SDS, EM-72.
Wear limit:
0.2 mm (0.008 in)
Out-of-round (X þ Y) standard:
Less than 0.015 mm (0.0006 in)
Taper (A þ B) standard:
Less than 0.01 mm (0.0004 in)
If it exceeds the limit, rebore all cylinders. Replace cylinder
block if necessary.
2. Check for score and seizure. If seizure is found, hone it.
+If cylinder block or piston is replaced, match piston grade
with grade number on cylinder block lower surface.
SEM258C
3. Measure piston skirt diameter.
Piston diameter ªAº:
Refer to SDS, EM-73.
Measuring point ªaº (Distance from the top):
Refer to SDS, EM-73.
4. Check that piston-to-bore clearance is within specification.
Piston-to-bore clearance = cylinder bore measurement
ªBº þ Piston diameter ªAº:
Refer to SDS, EM-73.
5. Determine piston oversize according to amount of cylinder
wear.
Oversize pistons are available for service. Refer to SDS EM-73.
6. Cylinder bore size is determined by adding piston-to-bore
clearance to piston diameter ªAº.
Rebored size calculation:
D=A+BþC
where,
D: Bored diameter
A: Piston diameter as measured
B: Piston-to-bore clearance
C: Honing allowance 0.02 mm (0.0008 in)
7. Install main bearing caps and tighten bolts to the specified
torque. This will prevent distortion of cylinder bores.
8. Cut cylinder bores.
+When any cylinder needs boring, all other cylinders must
also be bored.
+Do not cut too much out of cylinder bore at a time. Cut
only 0.05 mm (0.0020 in) or so at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
10. Measure finished cylinder bore for out-of-round and taper.
+Measurement should be done after cylinder bore cools
down.
CYLINDER BLOCKQG
Inspection (Cont'd)
EM-56
Page 135 of 2493

SEM316A
CRANKSHAFTNJEM0026S071. Check crankshaft main and pin journals for score, wear or
cracks.
2. With a micrometer, measure journals for taper and out-of-
round.
Out-of-round (X þ Y):
Less than 0.003 mm (0.0001 in)
Taper (A þ B):
Less than 0.004 mm (0.0002 in)
SEM346D
3. Measure crankshaft runout.
Runout (Total indicator reading):
Less than 0.04 mm (0.0016 in)
SEM366E
BEARING CLEARANCENJEM0026S08+Use Method A or Method B. Method A is preferred because it
is more accurate.
Method A (Using bore gauge and micrometer)
Main bearingNJEM0026S08011. Set main bearings in their proper positions on cylinder block
and main bearing cap.
SEM683G
2. Install main bearing cap to cylinder block.
Tighten all bolts in correct order in two or three stages. Refer
to EM-61.
3. Measure inner diameter ªAº of each main bearing.
AEM026
4. Measure outer diameter ªDmº of each main journal in crank-
shaft.
5. Calculate main bearing clearance.
Main bearing clearance = A þ Dm
Standard: 0.020 - 0.044 mm (0.0008 - 0.0017 in)
Limit: 0.1 mm (0.004 in)
If it exceeds the limit, replace bearing.
If clearance cannot be adjusted within standard of any bearing,
grind crankshaft journal and use undersized bearing.
CYLINDER BLOCKQG
Inspection (Cont'd)
EM-57
Page 136 of 2493

SEM588A
When grinding crank pin and crank journal:
+Grind until clearance is within specified standard bearing
clearance.
+Fillets should be finished as shown in the figure. R: 2.3 -
2.5 mm (0.091 - 0.098 in)
Refer to SDS, EM-75 for standard bearing clearance and
available spare parts.
SEM930F
6. If the crankshaft is replaced, select thickness of main bearings
as follows:
a. Grade number of each cylinder block main journal is punched
on the respective cylinder block. These numbers are punched
in either Arabic or Roman numerals.
AEM172
SEM194C
b. Grade number of each crankshaft main journal is punched on
the respective crankshaft. These numbers are punched in
either Arabic or Roman numerals.
c. Select main bearing with suitable thickness according to the
following table.
Main bearing grade color:
Crankshaft main jour-
nal grade numberCylinder block main journal grade number
012
0 Black Brown or Red Green
1 Brown or Red Green Yellow
2 Green Yellow Blue
For example:
Cylinder block main journal grade number: 1
Crankshaft main journal grade number: 2
Main bearing grade number=1+2=Yellow
AEM027
Connecting rod bearing (Big end)NJEM0026S08021. Install connecting rod bearing to connecting rod and cap.
2. Install connecting rod cap to connecting rod.
Tighten bolts to the specified torque.
3. Measure inner diameter ªCº of each bearing.
CYLINDER BLOCKQG
Inspection (Cont'd)
EM-58