Inspection and adjustment are required in the purchase and sale of motorcycles.
1. Vehicle inspection of motorcycles
First of all, the appearance inspection should be carried out. The parts of the vehicle should be in good condition and there are no missing parts. The paint layer, chrome layer and galvanized parts should be bright and shiny, without scratches and falling off. The vehicle shall have the product certificate, product instruction manual, and the on-board spare parts and tools shall be checked and accepted according to the packing list. Then carry out the starting inspection. Under normal temperature, the cold car should be started no more than three times, and the hot car should be successfully started once by foot. There should be no abnormality and knocking sound when the engine is running, the idle speed should be stable, and there should be no leakage of gasoline and oil.
2. Inspection and adjustment of components
(1) Front wheel brake. The front wheel brake is operated by the right hand and its free travel is checked first. The so-called free stroke refers to the stroke from the start of the handlebar to the start of the brake. If the stroke is too small, the front brake shoe and the front wheel brake drum cannot be completely separated, which affects the driving speed; if the stroke is too large, it affects the braking efficiency and cannot be braked in time.
(2) Rear wheel brake. The rear wheel brake is operated by foot pedal, first check the free travel of the brake pedal.
(3) Clutch. The clutch is generally operated by the left hand, and its free travel is checked when adjusting.
(4) Rear shock absorber.
(5) Rear transmission. The adjustment of the rear transmission is mainly to check the tightness of the transmission chain (transmission belt). The inspection part is in the middle position between the front and rear sprockets (pulleys). Use your fingers to move the chain up and down to see the distance of the up and down movement. For small motorcycles, it is 10～ 20 mm, ordinary motorcycles are 20 to 30 mm. For the tightness of the V-belt, press the belt by hand [with 49 N (5 kg force)], and the belt sags by 10-20 mm.
(6) Carburetor idle speed. Idle speed is the lowest stable speed when the engine is idling, when the throttle handle is in the minimum position, the engine can keep running continuously. When adjusting, start the engine first, gradually turn the throttle handle, and check the free stroke of the throttle handle, which is generally set at 2 to 6 mm. If the rotation does not exceed 2 mm, the engine speed will increase, indicating that the free stroke is too small; If the stroke exceeds 6 mm and the engine speed still does not increase, it means that the free stroke is too large.