Multi-cylinder engine motorcycle performance is advanced, the structure is complex, at present, there is not much reference, the engine failure, often difficult maintenance, in order to improve the maintenance effect, maintenance personnel in addition to the need to be familiar with the structure of multi-cylinder engine motorcycle, principle and internal connection, especially when the repair should pay attention to the following points.
1. before the demolition of the fault inquiry and test run
Any motorcycle will occur failure, failure occurs when there are signs and external performance. Before repair, maintenance personnel should be like a doctor to see a patient, to the owner of the car to ask carefully about the omen of the vehicle failure, external performance, may cause the fault and the owner ignored the related factors, such as what happened before the vehicle and the elimination of the situation. Any negligence may bring a lot of unnecessary trouble to the maintenance work. After asking clearly, maintenance personnel must personally test, hand touch, ear, eye, nose and smell, repeatedly experience the vehicle fault phenomenon, fault characteristics.
2, grasp the main fault factors and determine the parts to be disassembled
Motorcycle faults are complex and diverse, especially the motorcycle with multi-cylinder engine. There are often many factors leading to the same fault, and all factors interact and influence each other. The fault is not easy to accurately diagnose and completely eliminate. For this fault, maintenance personnel should not be anxious to dismantle the vehicle. First of all, according to the experience of the personal test drive, combined with the introduction of the owner, all the relevant factors that may cause this kind of failure are summarized, and the causal diagram is drawn. Consider the related factors in the diagram, grasp the main causes of failure, determine the parts where the fault occurs, and determine which parts need to be disassembled and inspected.
3, do a good job of dismantling records
According to the "first outside after inside, first easy after difficult" principle, in order to dismantle the car. For the motorcycle whose structure is not very familiar, record the parts according to the sequence of dismantling, including adjusting the assembly position of gaskets and other small parts. Assembly diagram should be drawn for parts with complex assembly relation.
4, the same name parts do color mark
There are many namesake parts in the heat engine of multi-cylinder engine. Although these namesake parts seem to have the same structure, shape and size, the wear and deformation of the namesake parts can not be consistent after a long time of use. As a cylinder of two exhaust valve wear is not consistent, if the two exhaust valve assembly after interchange, it is difficult to reliably seal between the exhaust valve and the exhaust valve seat. Therefore, the parts with the same name should not be exchanged as much as possible. The parts with the same name in the same cylinder are marked with color, and the parts with the same name removed from different cylinders are placed separately.
5, mark valve timing
The valve system of multi-cylinder engine is one of the most complex and critical systems of the engine. The marking methods of valve timing for different engines are often different. The valve timing and ignition timing are mutually coordinated and unified. For unfamiliar models, before disassembly of valve mechanism, it is necessary to explore the meaning and proofreading method of valve timing and ignition timing mark. If the mark is not right or ambiguous, please do your own marking and then remove it.
6. Loading requirements
After troubleshooting, the car shall be loaded according to the disassembly record, color marking and the reverse order of valve timing. During assembly, the sealing property of the engine cooling channel, oil channel, airway and each sealing surface shall be ensured, the scale, oil scale and carbon deposit shall be cleaned, and the air discharge in the cooling channel and hydraulic brake pipeline shall be clean, etc.
In short, the structure of multi-cylinder engine motorcycle is complex, there is not much reference information at present, it is difficult to repair, maintenance should not rush for success, blind disassembly, should be good at analysis, reliable method, cautious treatment