Page 1651 of 1659

General Specifications
Engine model TD25
Cylinder arrangementIn-line
Number of cylinders 4
Valve arrangement OHV
Bore x stroke mm (in)92.9 x 92.0
(3.657 x 3.622)
Displacement cm
3(cu in) 2,494 (152.18)
Firing order 1-3-4-2
Number of
piston ringsCompression 2
Oil 1
Number of main bearings 5
Inspection and Adjustment
COMPRESSION PRESSURE
Unit: kPa (bar, kg/cm2, psi)/rpm
Standard 2,942 (29.4, 30, 427)/200
Minimum 2,452 (24.5, 25, 356)/200
Differential limit between cylinders 294 (2.9, 3, 43)/200
CYLINDER HEAD
Unit: mm (in)
Standard Limit
Head surface distortionLess than
0.07 (0.0028)0.2 (0.008)
Nominal cylinder head height 89.9 - 90.1 (3.539 - 3.547)
VALVE
Unit: mm (in)
SEM188
Engine TD25
Valve head diameter ``D''
Intake41.4 - 41.6
(1.630 - 1.638)
Exhaust36.9 - 37.1
(1.453 - 1.461)
Valve length ``L''
Intake
117 (4.61)
Exhaust
Valve stem diameter ``d''
Intake 7.962 - 7.977 (0.3135 - 0.3141)
Exhaust 7.945 - 7.960 (0.3128 - 0.3134)
Valve seat angle ``a''
Intake
45É - 45É30¢
Exhaust
Valve margin ``T'' limit 0.5 (0.020)
Valve stem end surface
grinding limit0.2 (0.008)
Valve clearance (Hot)
Intake
0.35 (0.0138)
Exhaust
SERVICE DATA AND SPECIFICATIONS (SDS)TD
EM-98
Page 1652 of 1659

Valve guide
Unit: mm (in)
Standard Service
Valve guide outside diameter12.033 - 12.044
(0.4737 - 0.4742)Ð
Valve guide inner diameter
(Finished size)8.000 - 8.015
(0.3150 - 0.3156)
Cylinder head valve guide
hole diameter12.00 - 12.011
(0.4724 - 0.4729)Ð
Interference fit of valve guide0.022 - 0.044
(0.0009 - 0.0017)
Standard Max. tolerance
Stem to guide clearance
Intake0.023 - 0.053
(0.0009 - 0.0021)0.15 (0.0059)
Exhaust0.04 - 0.07
(0.0016 - 0.0028)0.20 (0.0079)
Valve deflection limit
Intake 0.30 (0.0118)
Exhaust 0.40 (0.0157)
Valve spring
Free length mm (in)
Painted red 53.4 (2.102)
Pressure height
mm/N (mm/kg, in/lb)
Painted red31.8/713.9 - 788.5
(31.8/72.8 - 80.4,
1.252/160.5 - 177.3)
Assembled height
mm/N (mm/kg, in/lb)
Standard42.3/314.8 - 361.9
(42.3/32.1 - 36.9,
1.665/70.8 - 81.4)
Limit42.3/270.7
(42.3/27.6, 1.665/60.9)
Out-of-square mm (in) 2.3 (0.091)
VALVE LIFTER AND PUSH ROD
Unit: mm (in)
Standard Limit
Valve lifter outer diameter25.960 - 25.970
(1.0220 - 1.0224)Ð
Cylinder block valve lifter
hole diameter26.000 - 26.033
(1.0236 - 1.0249)Ð
Valve lifter to lifter hole clear-
ance0.030 - 0.073
(0.0012 - 0.0029)0.20 (0.0079)
Push rod bend (TIR)*Less than
0.3 (0.012)0.5 (0.020)
*: Total indicator reading
Rocker shaft and rocker arm
Unit: mm (in)
Standard Limit
Rocker shaft
Outer diameter19.979 - 20.00
(0.7866 - 0.7874)Ð
Rocker shaft bend (TIR)0 - 0.15
(0 - 0.0059)Less than
0.30 (0.0118)
Rocker arm
Inner diameter20.014 - 20.035
(0.7880 - 0.7888)Ð
Clearance between rocker
arm and rocker shaft0.014 - 0.056
(0.0006 - 0.0022)0.15 (0.0059)
CYLINDER HEAD TO VALVE DISTANCE
Unit: mm (in)
SEM724C
Standard Limit
Intake0.7 - 1.3
(0.028 - 0.051)1.70 (0.067)
Exhaust0.7 - 1.3
(0.028 - 0.051)1.70 (0.067)
SERVICE DATA AND SPECIFICATIONS (SDS)TD
Inspection and Adjustment (Cont'd)
EM-99
Page 1654 of 1659
CAMSHAFT AND CAMSHAFT BEARING
Unit: mm (in)
Standard Limit
Camshaft journal to bush-
ing clearance
[Oil clearance]0.020 - 0.109
(0.0008 - 0.0043)0.15 (0.0059)
Camshaft journal diam-
eter
Front50.721 - 50.740
(1.9969 - 1.9976)Ð
2nd50.521 - 50.540
(1.9890 - 1.9898)Ð
3rd50.321 - 50.340
(1.9811 - 1.9819)Ð
4th50.121 - 50.140
(1.9733 - 1.9740)Ð
Rear49.921 - 49.940
(1.9654 - 1.9661)Ð
Camshaft bend (Total
indicator reading)Less than
0.02 (0.0008)0.06 (0.0024)
Camshaft end play0.08 - 0.28
(0.0031 - 0.0110)0.50 (0.0197)
EM671
Standard Limit
Cam height ``A''
Intake & Exhaust41.88 - 41.92
(1.6488 - 1.6504)41.40 (1.6299)
SERVICE DATA AND SPECIFICATIONS (SDS)TD
Inspection and Adjustment (Cont'd)
EM-101
Page 1655 of 1659
CYLINDER BLOCK AND CYLINDER LINER
Unit: mm (in)
DEM057-N
Nominal cylinder block height ``H''
(From crankshaft center)252.95 - 253.05 (9.9586 - 9.9626)
Surface flatness (Without cylinder liner)
StandardLess than 0.05 (0.0020)
Limit0.2 (0.008)
Cylinder bore (Without cylinder liner)
Inner diameter
Standard 95.900 - 95.920 (3.7756 - 3.7764)
Cylinder bore
Inner diameter
Standard
Grade No. 1 92.900 - 92.910 (3.6575 - 3.6579)
Grade No. 2 92.910 - 92.920 (3.6579 - 3.6583)
Grade No. 3 92.920 - 92.930 (3.6583 - 3.6587)
Wear limit0.20 (0.0079)
Out-of-round (X þ Y) standard Less than 0.020 (0.0008)
Taper (A þ B) standard Less than 0.020 (0.0008)
Projection ``S'' 0.02 - 0.09 (0.0008 - 0.0035)
Deviation of each cylinder ``S'' Less than 0.05 (0.0020)
Interference fit cylinder liner to block þ0.01 to 0.03 (þ0.0004 to 0.0012)
SERVICE DATA AND SPECIFICATIONS (SDS)TD
Inspection and Adjustment (Cont'd)
EM-102