7
STRATO CHARGED ENGINE
GZ25N
4. MAINTENANCE SPECIFICATIONS
4-1 Engine Block
Cylinder
Compression
8.7(124)
5.5(78)
Compression
kg/cm
2
(psi)
Gauge
Bore
ø34(1.339)
Peel off of plating or Cylinder
mm(in.)
expose of base met
Gauge
Piston
Piston dia.
ø33.96(1.3370)
ø33.86(1.3331)
Micrometer
At right angle to
mm(in.)
ø33.975(1.3376)
piston pin.
Piston Ring Groove Width mm(in.)
1.2(0.047)
1.3(0.051)
Thickness Gauge
Piston Pin Hole Bore mm(in.)
ø8(0.3150)
ø8.04(0.3165)
Cylinder Gauge
Clearance between
0.025(0.0010)
0.15(0.0059)
Micrometer /
Piston & Cylinder mm(in.)
0.065(0.0026)
Cylinder Gauge
Clearance between Groove
0.04 (0.0016)
0.1(0.0039)
Thickness
and Piston Ring mm(in.)
0.08(0.0031)
Gauge
Fitting between Piston Pin &
0.005T(0.00020T)
0.05L(0.0020L)
Micrometer /
Piston Pin Hole mm(in.)
0.011L(0.00043L)
Cylinder Gauge
Piston Ring
End Gap mm(in.)
0.1(0.0038)
0.5(0.0197)
Thickness Gauge
Measure at
0.3(0.0118
cylinder skirt.
Width mm(in.)
1.2(0.0472)
1.1(0.0433)
Micrometer
Piston Pin
Diameter mm(in.)
ø8(0.315)
ø7.98(0.314)
Micrometer
No stepwear is allowed
Connecting Rod
Small End Bore mm(in.)
ø11(0.433)
ø11.05(0.435)
Cylinder Gauge
Clearance between Small End Piston
0 0.021(0.0008)
0.045(0.0018)
Micrometer /
Pin & Needle Bearing mm(in.)
Cylinder Gauge
Clearance between Large End Crank
0.005(0.0002)
0.05(0.0020)
Micrometer /
Pin & Needle Bearing mm(in.)
0.028(0.0011)
Cylinder Gauge
Parallelness of Large/Small
–
0.15/100
Mandrel
End Bores mm(in.)
Dial Gauge
Crankshaft
Diameter at Main Bearing
ø12(0.4724)
ø11.97(0.4713)
Micrometer
(MAG, PTO) mm(in.)
Diameter at Oil Seal
ø12(0.472)
ø11.09(0.469)
Micrometer
(MAG, PTO) mm(in.)
Diameter at Clutch Drum
ø12(0.4724)
ø11.97(0.4713)
Micrometer
Bearing ( PTO) mm(in.)
Eccentricity mm(in.)
–
0.07(0.028)
Dial Gauge /
Adjust or exchange
Centre Support
Width between crank webs mm(in.)
22
21.9
22.1
Micrometer
Axial Play mm(in.) –
0.5(0.020)
Thickness Gauge
Main Bearing (Ball Bearing)
–
Flutter, irregular
noise generated
Clutch Drum
Bore at Bearing mm(in.) ø12
(0.472)
ø12.05(0.474)
Cylinder Gauge
Bore at Drum mm(in.)
ø54(2.126)
ø54.6(2.150)
Vernia Calipers
Maintenance Item
Standard
Limit
Remarks
Measuring
Instrument