Find a master to tell me something about motorcycles.
Some motorcycles have difficulty in cold starting in summer, especially in rainy days. After starting, the engine is unstable, easy to turn off, with symptoms of insufficient combustion, weak driving after starting, and the engine runs normally after driving for a period of time. ~}yF
If this happens, the spark plug should be removed for flashover test. If the spark is strong, the ignition system is normal. Carefully check whether there are any tiny cracks in the spark plug cap. At this time, put the spark plug cap loosely on the spark plug. If the engine is easy to start when the cold car is started, and there is a strong spark jumping sound between the spark plug caps, it means that there are tiny cracks in the spark plug caps, which will cause breakdown when the cold car is started in wet summer and rainy weather, leading to the failure of the spark plug. When the engine warms up, the air around the spark plug cap becomes relatively dry and the insulation resistance increases due to the heat emitted by the engine itself. At this time, the high pressure can not penetrate the air in the gap, and the engine returns to normal operation. ; =
Second, what is the reason for the motorcycle to automatically slow down and turn off during driving? How to rule it out? $q#LK
When the motorcycle is running, it will slow down gradually and the engine will turn off automatically. Before turning off the engine, it was obvious that the engine was weak. Generally speaking, the fuel supply system is out of order. At this time, check whether the fuel in the fuel tank is used up. If there is enough fuel, check whether the fuel switch is turned on, and then unplug the oil pipe to check whether there is fuel supply. If there is no oil supply, it means that the carburetor oil circuit is blocked and should be unblocked. G2q4
The simple way to remove the fault is to turn the switch to the off position, then remove the oil pipe connected to the oil tank switch, and then blow the oil pipe with your mouth (or inflate it with a pump). After the impact of compressed air, the blocked oil circuit in the carburetor may be unblocked. If the oil circuit is still blocked, it means that the oil circuit is seriously blocked, and the carburetor should be removed and thoroughly cleaned. +=j(
If the engine makes a loud "snapping" sound when the engine is turned off, it can't be started after the engine is turned off, and the compression force is very small when the starting lever is stepped on, it can be concluded that the cylinder head gasket has been burned through or the crankcase oil seal is damaged. Four-stroke engine should also consider factors such as valve burning, air leakage and valve tappet bending. The valve cover and air cushion can be removed for inspection. If the cylinder gasket is worn, it should be replaced with a new one. If the cylinder gasket is not damaged, check whether the crankcase oil seal is damaged. Remove the parts outside the crankcase oil seal and take out the oil seal for inspection. If the oil seal is damaged, please replace it with a new one. Mikzl
Third, how to adjust the oil pump flow of separation lubrication+3; = 1
The flow of the oil pump should match the opening of the carburetor throttle valve. If the supply of lubricating oil is too large, the combustion is insufficient, the muffler emits black smoke, which makes it difficult to start, and the spark plug is easy to deposit carbon. If the supply of lubricating oil is too small, the engine will overheat, the wear will increase, and even the cylinder will expand. It can be seen that it is very important to synchronize the flow of oil pump with the supply of gasoline. Generally, the oil pump flow should be adjusted once every 6000 kilometers. The oil pump flow is controlled by the control cable. By adjusting the length of the cable, the flow of the oil pump can be changed. /K})Hl
The adjustment sequence is as follows: m
1. Remove the carburetor inspection cover, engine sprocket cover and oil pump cover; /
2. Turn the throttle handle inward to the end to make the throttle fully open, align the scale line on the throttle with the highest point on the circumference of the carburetor air inlet, and keep the throttle at this position; Yengham
3. Loosen the lock nut on the cable sheath and tighten the adjusting stud, so that the mark on the control rod is aligned with the mark on the pump body; {
4. Check again. If there is no abnormality, finally tighten the lock nut. Coronary heart disease intensive care unit
Four. What does the maintenance adjustment of clutch include? dbD
The maintenance and adjustment of clutch mainly includes the inspection of clutch engagement and disengagement, the adjustment of free stroke of clutch handle, the adjustment of spring force, the cleaning of clutch friction plate and the lubrication of bearing. L
The newly manufactured motorcycle clutch has been adjusted. After a period of use, the clutch will not completely separate or slip due to the elongation of the control cable, the normal wear of the clutch friction plate and the looseness of the adjusting bolt. PumB
The characteristics of incomplete clutch separation are that when the motorcycle starts, the clutch handle is not loosened and the vehicle moves forward; When shifting gears, the clutch grip has been clenched, but there is still a sense of gear collapse, making shifting difficult; When braking, although the clutch grip has been tightened, it will still cause the engine to stall. L]fd "
Clutch slip is characterized by poor acceleration performance when motorcycle starts or shifts gears; When going uphill, the vehicle is not firm; When driving, the speed is not high. If the above characteristics appear, the road test method should be used to further judge whether the clutch slips. During the road test, put the motorcycle into low gear, drive at the speed of 15km, brake slowly and refuel, and listen to the engine running sound. If the sound changes, the clutch is well engaged; If the sound does not change obviously, it means that the clutch is slipping or has poor contact, and it should be adjusted in time. | DX & ltX
5. Why is the motorcycle's fuel tank above the engine? What's the hole in the tank cover for? 9B[KzL
Motorcycle engines generally use gravity fuel supply, that is, the fuel in the fuel tank flows into the carburetor by its own weight. There is a small vent hole on the motorcycle fuel tank cover to keep the inside of the fuel tank connected with the outside atmosphere. If there is no small vent hole in the tank cover, then the tank is a completely closed container. When the fuel level drops after fuel consumption, a vacuum will be formed in the fuel tank, which will prevent the fuel from flowing out normally and affect the normal fuel supply of the engine. If the small vent hole on the fuel tank cover is blocked, it should be opened in time, otherwise it will affect the normal operation of the engine. , I
Some motorcycles also put the fuel tank under the engine for structural needs. In this case, a gasoline pump must be installed to supply oil to the engine, and the gasoline pump is driven by the engine. Similarly, the small hole in the tank cover is also indispensable. & lt
6. What is the reason why the battery can't be charged? How to diagnose? X3
Whether the battery is charged or not refers to that the battery is charged for a long time and the voltage rises slowly when the engine works normally. The reasons are as follows: B0*
1. Loose or rusty terminals in the charging circuit will increase the resistance and reduce the current intensity. ^#
2. Sulfide the battery plate, so that a layer of white aluminum sulfate particles with poor conductivity is attached to its surface. After the coarse particles block the pores of the plate, the electrolyte is difficult to penetrate, which leads to the increase of internal resistance and the inability of current to pass through. (Ci
3. The battery panel is damaged due to heavy current charging and discharging, excessive electrolyte specific gravity or insufficient liquid level. 5B & gt8n3
When diagnosing, first check whether each terminal is loose or corroded, and then judge whether the electrode plate is vulcanized according to the phenomenon during charging. If the electrolyte temperature rises rapidly during charging, or the charging time is not long, a large number of bubbles are generated in the electrolyte, but the voltage does not rise and the specific gravity of the electrolyte does not increase, indicating that the electrode sheet has been vulcanized. When the vulcanization is not serious, pour out all the electrolyte, inject distilled water, and then charge aluminum sulfate with a small current of about 2 amps for a long time, but be careful not to let the battery temperature rise. When the specific gravity of the electrolyte does not increase within several hours, it indicates that the battery is fully charged before discharge. After repeated charge and discharge cycles, if the active substance is still abnormal, the electrode sheet should be replaced. }0fa5
How does the caliper brake device (disc brake) work? V^n！ "b
At present, more and more motorcycles use butterfly braking, especially front braking. The caliper brake device consists of hydraulic oil control caliper and brake disc. The brake caliper and the front fork guide tube are fixed together and are the fixed parts of the braking device. The brake disc is fixed with the wheel and rotates with the wheel, which is the rotating part of the braking device. One end of the hydraulic oil pipe is connected to the oil cylinder on the brake caliper, and the other end is connected to the plunger valve on the handlebar, and it is filled with hydraulic oil. The brake caliper consists of two cylinders, and the front end of each cylinder is provided with a square friction plate. When the brake pedal is depressed (or the hand brake handle is clenched), the plunger valve acts to push the hydraulic oil to flow into the two cylinders of the brake caliper along the hydraulic oil pipe. Under the action of pressure oil, the oil cylinder pushes the friction plate close to the brake disc, so that the friction plates on both sides are completely attached to the two end faces of the brake disc until the brake disc is clamped, which produces huge friction resistance and forces the wheel to stop rotating, thus achieving the purpose of stopping or slowing down. When the brake pedal (or manual brake handle) is released, the pressure in the oil circuit quickly drops to zero, and the oil cylinder drives the friction plate to return to its original position to release the brake. g & gt6.& lt
The braking torque of the caliper brake device is not only related to the cylinder pressure, but also related to the diameter of the brake disc. By selecting brake discs with different diameters, the braking torque of front and rear wheels can be balanced and the best braking effect can be achieved. +-c？ three
Eight, how to clean the fuel tank? V+[Cb
Motorcycle fuel tank is formed by stamping and roll welding of thin steel plate. In order to prevent the corrosion of gasoline, the inner surface of the fuel tank is sandblasted, phosphatized or glazed. The top surface of the oil tank is provided with an oil filler, and the oil filler is provided with an oil tank cover with a rubber band. A small vent hole is drilled on the tank cover to keep the inside of the tank connected with the atmosphere. Clear (short for clear)
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Clean the fuel tank of the motorcycle every 5000-6000 km. When cleaning the fuel tank, pay attention to the following items.
1. When cleaning the fuel tank, the fuel tank must be removed. First, unscrew the fixing bolts of the fuel tank, unload the fuel tank, then install a small amount of gasoline, and move the fuel tank up and down for impact cleaning. If the inner wall of the oil tank has rusted, a small amount of iron ore or waste nuts can be put in and repeatedly impacted, and finally washed with gasoline several times until it is clean. 1h*h
2. If there is oil leakage or oil leakage in the oil tank, it can be repaired by gas welding or tin welding. Before welding repair, wash the oil tank with boiling water for many times, dry it, and then weld repair. Otherwise, the residual gasoline in the fuel tank will burn due to the high temperature of welding repair, which will lead to the explosion of the fuel tank and cause an accident. %MD
3. The fuel tank switch should be disassembled for cleaning, and the dirt on the filter screen should be cleaned with a brush. Never wipe the parts of the fuel tank switch and the inner wall of the fuel tank with cotton yarn to avoid blocking the carburetor. z
4. The hole on the box cover should be kept clear, and it should be connected if it is blocked. The rubber gasket on the tank cover should be kept intact. If it is damaged, it can be prepared with oil-resistant rubber.