Generic Trigger SM 50ccm, Owner'S Manual

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12 Crankcase/clutch/actuating lever
Preparation data ----------------12.1
Fault diagnosis -----------------12.2
Crankcase -----------------------12.3
Clutch ---------------------------12.4
Actuating lever -----------------12.5
12.1 Preparation data
Matters needing attention in operation
Since the crankcase is a thin-section casting, please avoid impact on it during operation in case there is any
distortion or rupture.
All parts should be cleaned before inspection and test and should be blow dry with high pressure air.
Before operation, discharge the lubricating oil in the crankcase.
Function of the crankcase
：
the bearing part of the engine.
Its primary function is supporting the
crankshaft, clutch, gearbox, cylinder body as well as the cylinder cover and bearing bursting impact of
combustion and movement inertia force of crankshaft connecting rod system and constituting some closed
（ oil, air seal) space. The crankcase has a hanging hole which links the engine and the frame with other parts
by connecting with the hanging hole.
Preparation reference
Unit ： mm
Item Standard value Allowable limit
clearance of connecting
rod big end in right and left
direction
0.1-0.35 0.55
axial clearance of
connecting rod big end in
vertical angle
0-0.008 0.05
Crankshaft
vibration 0.1
Thickness of wearing plate 2.9-3 2.6
Clutch
Length of pressure spring 29.4-30.6 29.0
Bore diameter of shift fork 7.825-7.845 7.91
Thickness of shift fork 3.95-4.05 3.9
Outer diameter of shift drum 41.8-42 41.75
Shift
mechanism
Locked groove width of shift
drum
6.05-6.15 6.3
Tools
Multiple use fixer Clutch spring compressors
Driver's perch Box spanner
Guide rod Bearing driver