RedMax GZ25N - 4. MAINTENANCE SPECIFICATIONS; 4-1 Engine Block

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
ø
34(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