The motorcycle certificate will contain detailed information such as the vehicle's manufacturer, address, frame number, and engine number. If the car you buy has been registered, the certificate must be deposited with the traffic police team. file, otherwise it should be in the hands of the original owner together with the invoice.

For a car without an invoice, the most important thing is to confirm that the car is not a black car. If conditions permit, you can go to the car dealership where the car was originally purchased to check, or ask the original car owner to contact the car dealership. Contact the seller and provide a piece of certification. If this is difficult, you can sign an agreement with the seller, and the seller will promise that the source of the car is legal.

If you want to sell this car again in the future, you have to use this method. If the car has been registered, you can go to the traffic control department for verification. However, if the car has not been registered, it cannot be registered without the necessary procedures. ?

1. According to national regulations, motorcycles must have a motorcycle certificate when leaving the factory, and it must follow the vehicle. Wherever the car goes, the certificate will follow.

2. Motorcycles without certificates are vehicles purchased with bank loans. Only after all these vehicles have been sold and the bank loans repaid can the certificates be obtained. If the vehicles are sold quickly, It’s faster to get the certificate. If you can’t sell it for a few months, you won’t be able to get the certificate for several months. If you don’t have a certificate, you can’t go through the registration procedures and naturally you can’t go on the road. I bought a motorcycle. If you can't open it and leave it at home, wouldn't it be a waste of money?

3. Therefore, it is best not to buy a motorcycle without a certificate, because no one knows when the certificate will be obtained.

Extended information:

1. Characteristics of motorcycle engines:

(1) The engine is a two-stroke or four-stroke gasoline engine.

(2) Air cooling is used, and there are two types: natural air cooling and forced air cooling. General models use natural air cooling, which relies on the air blowing through the cylinder head and the radiator on the cylinder liner to take away heat while driving. In order to ensure the cooling of the high-power motorcycle engine at low vehicle speeds and before starting, the forced air cooling method is installed with fans and air ducts and uses forced air to blow the cooling fins.

(3) The engine speed is high, generally above 5000 rpm. The power per liter (effective power emitted per liter of engine displacement) is large, generally around 60 kW/liter. This shows that the motorcycle engine has a high degree of reinforcement and the engine has a small overall size.

(4) The engine crankcase, clutch and gearbox are designed to be integrated with a compact structure.

2. Body:

The body consists of three parts: cylinder head, cylinder block and crankcase. The cylinder head is made of aluminum alloy and has a heat sink. The new four-stroke motorcycle engine is It adopts overhead valve, chain drive and overhead camshaft structure. The cylinder block material is mostly bimetal (wear-resistant cast iron cylinder liner with aluminum heat sink cast outside) to achieve better heat dissipation effect.

Some motorcycles use wear-resistant cast iron cylinders, such as the Yangtze River 750 and Jialing JH70. In some small light motorcycles, such as the Yuhe YH50Q small-displacement (50 cubic centimeter) engine, aluminum alloy is used The inner wall of the cylinder is plated with a 0.15mm hard chromium layer. The crankcase is made of aluminum alloy die-casting and is composed of two left and right boxes. Some motorcycles have buffer blocks between the heat sinks to suppress the noise caused by the vibration of the heat sink.

3. Crank connecting rod:

The crankshaft of the motorcycle engine is a combined type, which is composed of a left half crankshaft, a right half crankshaft and a crank pin. The main journals of the left and right half-shafts are equipped with ball bearings to support the crankshaft on the crankcase. The two ends of the crankshaft are equipped with flywheel, magneto and clutch driving gear respectively. The connecting rod has an integral structure, and the big end is annular. It is equipped with needle roller bearings and crank pins to form a crank connecting rod group.

When installing the piston ring in a two-stroke engine, attention should be paid to aligning the opening of the piston ring with the positioning pin in the piston ring groove to prevent the piston ring from rotating in the ring groove, causing air leakage and scratches. The inlet and exhaust ports on the cylinder liner.

4. Carburetor:

The carburetor is an important component in the motorcycle fuel supply system, located between the air filter and the engine air inlet.

Generally, motorcycle engines use a flat-suction type with an intake airflow direction, a plunger type throttle valve, and a float chamber type carburetor. The carburetor structure is mainly composed of two parts: the float chamber and the mixing chamber.

The float chamber is located below the carburetor. There is an oil pipe leading to the fuel tank through the throttle switch. Through the needle valve on the float, the oil level in the float chamber is maintained at a certain height to stabilize the oil supply pressure. The function of the mixing chamber is to mix the evaporated atomized gasoline with air so that the engine can obtain the required mixture under various loads and speeds. It consists of a festival valve, an injection needle, an injection pipe, a gas and an oil passage, etc.

The rotation of the motorcycle throttle handle drives the throttle wire rope to control the up and down movement of the throttle valve and the fuel injection needle, changing the intake throat section and fuel supply volume to adapt to the mixing under different speeds and loads. The need for anger. There is an idle speed adjustment screw on one side of the carburetor to adjust the idle speed. The idle stop screw is used to prevent the throttle valve from rotating and adjust the minimum opening of the throttle valve. There is a return spring above the throttle valve, which keeps the throttle valve closed when the throttle handle is not turned.

On some two-stroke motorcycle engines, in order to avoid back-injection in the carburetor at low speeds, a one-way reed valve is installed between the carburetor and the cylinder block to control the air intake. The reed is made of thin spring steel sheets, and the valve seat is made of aluminum alloy. It has an air inlet on it. The plane of the air inlet and the contact part of the reed are pasted with a layer of oil rubber to reduce the impact and vibration of the reed and the valve seat. .

During suction, a certain degree of vacuum is formed in the crankcase. Under the action of the pressure difference, the reed valve opens and the mixture enters the crankcase. When the piston moves downward and the ventilation port has not yet opened, the crankcase The internal pressure increases and the reed valve closes to prevent the mixture from flowing back, improving the power and economy of the engine at low speeds.

5. Lubrication system:

The four-stroke engine adopts a lubrication method that combines splash lubrication and pressure lubrication. Two-stroke engines generally use a mixed lubrication method in which a certain proportion of QB-grade gasoline engine oil is mixed into gasoline.

However, the mixed oil of this lubrication method supplies lubricating oil in a predetermined proportion regardless of the engine operating conditions, which increases lubricating oil consumption, incomplete combustion, more carbon deposits, and exhaust gas. pollute.

The new generation of two-stroke engines all adopt separate lubrication methods and are equipped with separate lubrication oil tanks and oil pumps. The oil pump generally adopts a reciprocating plunger type variable oil supply oil pump, which is driven by the crankshaft gear through a worm gear and a worm. The oil supply is linked with the carburetor throttle valve through the throttle handle, control cable, and the carburetor throttle valve, so that the oil supply changes with the change of the engine speed. More oil is supplied at high speeds, and less oil is supplied at low speeds. The oil supply is reasonable and combined with mixed lubrication. Compared with other methods, it can save more engine oil.

The engine oil is blown into tiny oil mist by the high-speed mixture, which is supplied to parts that need lubrication, reducing the amount of oil entering the combustion chamber. The mixture burns completely, reducing carbon deposits and exhaust pollution.

Reference: Vehicle Certificate-Baidu Encyclopedia