Qianjiang QJ150T-10, Operation And Maintenance Manual, Page: 117 / 131

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15 Crankcase
Preparation data ---------------15.1
Fault diagnosis-----------------15.2
Crankcase
--------------------15.3
Installation ---------------------15.4
15.1
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
Crankshaft
Radial clearance of the big end of
connecting rod
0.008-0.016 0.05
Tools
Multiple use fixer Clutch spring compressors
Driver's perch Box spanner
Guide rod Bearing driver
15.2
Fault diagnosis
Strange noises in crankcase
Parts shattered or broken in crankcase The crankshaft bearings are loosened.
The bearings of crankshaft pin are loosened. Clutch depressed