BRP Johnson 4HP - Page 18

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GENERAL INFORMATION
*SPECIFICATIONS
Item Unit Data
CYLINDER/PISTON/PISTON RING
Cylinder distortion Limit mm (in) 0.05 (0.002)
Piston to cylinder clearance STD mm (in) 0.010 – 0.040 (0.0004 – 0.0016)
Limit mm (in) 0.100 (0.0039)
Cylinder bore STD mm (in) 62.000 – 62.015 (2.4409 – 2.4415)
Cylinder measuring position mm (in) 35 (1.4) from cylinder top surface
Piston skirt diameter STD mm (in) 61.975 – 61.990 (2.4400 – 2.4406)
Piston measuring position mm (in) 14 (0.6) from piston skirt end
Cylinder bore wear Limit mm (in) 0.100 (0.0039)
Piston ring end gap 1st STD mm (in) 0.20 – 0.35 (0.008 – 0.014)
Limit mm (in) 0.70 (.028)
2nd STD mm (in) 0.35 – 0.50 (0.014 – 0.020)
Limit mm (in) 1.00 (0.039)
Piston ring free end gap 1st, 2nd STD mm (in) Approx. 8.5 (0.33)
Limit mm (in) 6.8 (0.27)
Piston ring to groove
clearance
1st, 2nd STD mm (in) 0.03 – 0.07 (0.001 – 0.003)
Limit mm (in) 0.12 (0.005)
Piston ring groove width 1st, 2nd STD mm (in) 1.22 – 1.24 (0.048 – 0.049)
Oil STD mm (in) 2.51 – 2.53 (0.099 – 0.100)
Piston ring thickness 1st, 2nd STD mm (in) 1.17 – 1.19 (0.046 – 0.047)
Pin clearance in piston pin hole STD mm (in) 0.006 – 0.019 (0.0002 – 0.0007)
Limit mm (in) 0.040 (0.0016)
Piston pin outside diameter STD mm (in) 17.995 – 18.000 (0.7085 – 0.7087)
Limit mm (in) 17.980 (0.7079)
Piston pin hole diameter STD mm (in) 18.006 – 18.014 (0.7089 – 0.7092)
Limit mm (in) 18.030 (0.7098)
Pin clearance in conrod small end STD mm (in) 0.006 – 0.019 (0.0002 – 0.0007)
Limit mm (in) 0.050 (0.0020)