BRP Johnson 4HP, Service Manual, Page: 19 / 185

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GENERAL INFORMATION
*SPECIFICATIONS
Item Unit Data
CRANKSHAFT / CONROD
Conrod small end inside diameter STD mm (in) 18.006 – 18.014 (0.7089 – 0.7092)
Limit mm (in) 18.040 (0.7102)
Conrod big end oil clearance STD mm (in) 0.015 – 0.035 (0.0006 – 0.0014)
Limit mm (in) 0.080 (0.0031)
Conrod big end inside diameter STD mm (in) 28.015 – 28.025 (1.1030 – 1.1033)
Crank pin outside diameter STD mm (in) 27.990 – 28.000 (1.1020 – 1.1024)
Crank pin outside diameter difference
(out-of-round and taper) Limit mm (in) 0.010 (0.0004)
Conrod big end side clearance STD mm (in) 0.20 – 0.90 (0.008 – 0.0035)
Limit mm (in) 1.20 (0.047)
Conrod big end width STD mm (in) 23.30 – 23.80 (0.917 – 0.937)
Crank pin width STD mm (in) 24.00 – 24.20 (0.945 – 0.953)
Crankshaft runout Limit mm (in) 0.05 (0.002)
Crankshaft lower journal oil clearance STD mm (in) 0.020 – 0.062 (0.0008 – 0.0024)
Limit mm (in) 0.100 (0.0039)
Crankcase lower holder inside diameter STD mm (in) 25.000 – 25.021 (0.9843 – 0.9851)
Crankshaft lower journal outside
diameter STD mm (in) 24.959 – 24.980 (0.9826 – 0.9835)