XVI Crankcase
Preparatory data-----------------16.1
Fault diagnosis--------------16.2
Crankcase--------------------16.3
16.1 Preparatory Data
Precautions on Operation
Attention: Crankcase is a thin-wall casting part. Avoid impact on it during operation in case it may be
distorted or broken.
Clean carefully all the components before inspection and test and purge them with high-pressure gas.
Drain the lubricating oil from crankcase before working on it.
Function of crankcase:
Crankcase is the force bearing part of engine. It is mainly used to support
crankshaft, clutch, transmission, cylinder block and cylinder head. It bears impact from combustion
and inertia force from movement of crankshaft connecting rod; and forms a partial enclosed space (for
air and oil)
.
Suspension hole is set on the crankcase, which can be connected with the suspension hole in the vehicle block so that
the engine can be linked together with frame and other parts.
Basic data
Unit
：
mm
Item Standard
Allowable
limit
Crankshaft
Connecting rod big end left and right clearance
0.1-0.35
0.55
Connecting rod big end radial clearance
0.008-0.012
0.05
Shimmy 0.03
0.1
Tools
Universal fixer Clutch spring compressor
Screwdriver rod Socket wrench
Guide rod Bearing screwdriver
16.2 Fault Diagnosis
Noise in the Crankcase Engine stops automatically
Spare pars falling off or broken in the crankcase
Stuck clutch