KAYO MOTOR TD125, Service Manual

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rod
Radial backlash at big
end of connecting rod
0.004~0.012 0.015
Fault symptom and cause analysis
No.
Fault symptom Cause analysis
Remark
1 Shift difficulty
The shift fork is bent and deformed
Gaskets and bolts of speed drum loose and
loose
2 G roove-skipping
The pawl of the shift gear is worn
The shift fork is bent or worn
3 Crankshaft noise
The needle roller bearing at the big end of the
connecting rod is worn
Connecting rod bending
The crankshaft bearing is worn
4
Main and countershaft gear
noise
The main and countershaft gears are worn
The spline shaft is worn
Decomposition of crankcase
The decomposition steps of crankcase are as follows:
1. Place the right crankcase of the engine upward, remove the starting shaft retainer ring, remove the starting shaft
return spring and the starting shaft return spring seat;
2. Place the left crankcase of the engine upward; Remove 1 GB/T 5787/ M6x12 bolt and baffle at the hole of the
variable speed drum, take out the rubber plug, take out 1 GB/T 5787/ M6x16 bolt and the washer of the variable
speed drum;
3. Remove 4 GB/ T5777-M6x65 bolts, 2 GB/ T5777-M6x6 bolts and 1 GB/T5787 / M6x50 bolts, turn the
crankcase to separate the left crankcase from the right crankcase, and remove 2 positioning pins and crankcase
gaskets.
Disassembly of crankshaft, main and auxiliary
shaft
Disassembly of crankshaft, main and auxiliary shaft
1. Take out the crankshaft assembly from the box;
2. Take out the fork shaft, fork, speed change drum and
main and auxiliary shaft assembly from the box.
Note: ensure that no parts are left behind when taking
the main and secondary shaft components.
Decomposition of variable speed drum