1. The operation environment should be dustproof and windproof, and the operation should be standardized
Some motorcycle repair shops overhaul the engine in the outdoor operation, they do not matter how dusty, just replace. I don't know, dust mixed with the machine will cause undue abrasive wear, in this environment for the new oil may be dirtier than the old oil, overhaul the engine must be carried out indoors. In addition, the operation to the specification, the dismantling of the dismantling, should not move do not move. If CC125 variable speed CAM and fork, the engine left box does not have to open, the crankshaft does not have to take off, you can change the variable speed mechanism. If the wrong operation will cause unnecessary trouble, not only missed work, but also may cause poor side box seal. The prerequisite for repairing an engine is to know it like the palm of your hand and understand the engine parts structure diagram carefully.
2, the engine shell before cleaning is indispensable
During the overhaul of the engine housing has a lot of oil and dust accumulation, if not timely cleaning, these impurities will be in the removal of the engine into the body, after installation, to the relevant parts bring unnecessary wear. Again, foreign matter falls into the engine, will block the oil channel, and will therefore lead to poor lubrication, resulting in cylinder, shaft, clutch sintering. In addition, the engine housing has not been cleaned, when closing the box, foreign matter will be stuck in the box joint, affect the seal, resulting in oil seepage, oil leakage. Cleaning the engine housing also prevents the sludge from covering the bolts so they do not leak. For example, there are two fixing bolts in the box of Chongqing 80 engine, which can be easily covered by oil sludge. If they are missed and removed by force, the engine box will be damaged.
3. Marking is important
Whether it is a mature model or a transitional model, there are a wide variety of motorcycle engines with different structural characteristics. When we break down all kinds of engine, should do well in the installation of a variety of accessories tag, some nut thread is the same, but different appearance, should do well, not any installation, because all kinds of nut has a certain torque requirements, various shapes is set after many experiments, has certain scientific basis, if the swap, will affect its fixed effect, trigger a new fault. For example, the CG125 clutch fixing nut and crankshaft right end oil filter nut have the same internal thread, although they can be installed after exchange, but they are different in shape and torque, the clutch fixing nut is much more torque than the crankshaft fixing nut. When we disassemble engines of models we are not familiar with, such as CB125T, CBR400, etc., we should also mark the disassembled parts to prevent wrong or missing assembly.
4. Use special tools and utensils
The use of tools directly affects the quality and efficiency of maintenance work. Special tools are designed for the maintenance of specified parts, scientific and easy to use, labor saving, do not hurt accessories, such as afraid of trouble, drawing money, take a tool to operate against the rules will make work quality greatly reduced. For example, after the GY6 machine is removed, the clutch fixing nut can be removed smoothly with the 19# socket wrench and the brake. It can be seen that some repair shops do not have special tools, so they take a steel punch to savage disassembly. The nut is removed. The clutch assembly will fall off if the clutch fixed nut is loosened for a long time. There was a motorcycle overhaul soon after the clutch came off and caused the side box to break. Improper operation can also damage the bearing on the inner end of the output shaft.
In addition, when we take apart the engine, should be cleaned before and after the parts placed in order in the special aluminum plate or wooden plate, can not be stacked everywhere, some very small parts are easily lost, such as the crankshaft half key, piston pin retainer ring, a variety of spring gasket positioning pins.
5. Accessories shall be placed in order
When decomposing unfamiliar engines, it is necessary to put the parts in order to prevent leakage and wrong loading. For example, when changing gear of each engine, in the replacement of damaged parts, put the parts into place one by one from left to right, and assemble them in reverse order after replacing new products, so as not to cause mistakes.
6. The cleaning of relevant parts is critical
Once the engine is disassembled, each gasket (paper, asbestos and other gaskets) will promote the elasticity and promote the sealing effect after use. It cannot be used any more, and the replacement of new products should be thoroughly eliminated. In addition, no gasket sealing parts to use bamboo pieces to carefully remove the failed sealant (DX100, AX100, K100, and other two stroke engine box), and then, evenly applied to the quality of the special seal box fasteners. Remove all the parts and the parts with the oil sludge of the void and apply the bamboo chip to thoroughly remove, such as CG125 oil filter and C100 clutch hard sundries. This work also determines the use of the engine after the overhaul. Some maintenance workers just replace the damaged parts, do not replace the tired oil seal, gasket, spring, also do not clean the machine inside the sludge, impurities, installed on the shelf, although the car can ride, but not for a long time, the new fault will appear.
7. Carefully measure and compare the replacement parts
Accessories market mixed, in order to ensure the maintenance quality, at the same time to buy genuine parts and new pieces carefully compared, the use of special tools to actually measure, require the overhaul of the engine intact as before. If the crankshaft, cylinder components and other parts are replaced, the standard of each part of the crankshaft assembly should be measured with a vernier caliper, and the matching of the cylinder plug ring should be measured to avoid the problems found only after the fitting is finished and the cost of labor lost.