Cylinder block is the main part that affects the service life of motorcycle.
1. Pay attention to maintain the filtering effect of air filter. If there is dust in the engine running process into the cylinder block, it will cause the cylinder block early wear, so strictly prohibit not to install the air filter driving and do not clean the air filter for a long time.
2. New car running in strict accordance with regulations. The surface roughness of the new cylinder is very high, but its microstructure is still uneven. In the new car running in the period of increasing load, can be raised on the surface of the part gradually smooth, so as to extend the service life; If you do not run in the use of the maximum load, it is easy to pull the cylinder surface. Run in good cylinder, life can reach more than 80 thousand kilometers.
3. Use adequate quality lubricant. Install the new cylinder block with a coat of grease. When using mixed oil for lubrication, the mixing ratio of the run-in period is 18∶1, and 22∶1 in normal use. The best choice of lubricating oil brand two-stroke lubricating oil, this oil viscosity is small, coke plate value is low, less carbon after combustion. When there is no two-stroke oil, choose no. 10 motor oil.
4. Remove carbon periodically. A two-stroke engine burns gasoline and oil together to provide power and lubrication. Oil combustion in the combustion room after a large number of carbon, such as not timely cleaning, carbon into the cylinder block, easy to make the cylinder block broken. Generally, carbon accumulation should be removed from the cylinder head and piston top every 1000km.
5. If the engine power decreases obviously, the oil consumption increases obviously, and the inner surface of the cylinder body feels obvious wear traces by hand. When the gap between the cylinder body and the piston exceeds 0.15mm, the cylinder body should be lined out with large cylinder diameter and the piston with larger size should be replaced.
Cylinder lining, each increase of 0.25mm on the original size is a level. Lining cylinder after all the upper and lower edge of the air mouth must use a small file and asphalt to remove rough edges, and clean with gasoline, coated with oil. The matching gap between the cylinder body after lining and the new piston should be 0.05 ~ 0.07mm (the bottom skirt of the piston is perpendicular to the piston pin).
Motorcycle spark plug
1. The life of spark plug is generally 6000km. When replacing spark plug, please use the model required by the original machine. Carbon accumulation of spark plug should be cleaned every 1000km drive. Metal blade, metal brush or fire baking are not allowed to be used in the cleaning process. Wood pick should be used for cleaning
2. Only one sealing gasket is allowed to be used when installing spark plug, and it shall not be used multi-purpose or unused. Use a special wrench to tighten the spark plug. The tightening torque is: 10mm spark plug 14.7n, 12mm spark plug 24.5n, 14mm spark plug 29.4n. Too little pressure will leak, too much pressure will damage cylinder head thread.
3. If the engine breaks when driving, it may be caused by the carbon connection between the spark plug electrodes. Remove the spark plug and remove interelectrode carbon.
4. The color of spark plug electrode reflects the oil supply of carburetor. If the electrode is white, the mixture provided by the carburetor is too thin. If the electrode is black, the mixture is too thick. If the electrode is light brown, the mixture concentration is normal.
5. Generally, the spark plug electrode gap should be maintained between 0.6 and 0.7mm, which can be checked with a feeler. If the electrode burns, the gap should be adjusted in time. If the electrode burns seriously, the spark plug should be replaced in time to avoid the electrode falling into the cylinder and causing cylinder pulling.
1. The clutch is the mechanism to transfer or cut the power between the engine and the gearbox. Clutch joint is not good, power can not be fully transmitted to the rear wheel, it will affect the vehicle speed; Poor clutch release causes difficulty in shifting gears.
2. Whether the clutch joint is good depends on the following factors.
(1) the friction coefficient of clutch friction plate should be large enough. Friction pad materials generally have cork, nitrile butadiene rubber, asbestos rubber, paper, etc., the friction coefficient from large to small.
(2) the clutch spring must have sufficient pressure. After the clutch friction plate wear, its thickness becomes thinner, the spring pressure on the friction plate will reduce, at this time must replace the friction plate. Pay attention not to often half grip clutch, lest clutch early wear.
(3) the clutch handle must have sufficient free travel. The general free stroke is 10 ~ 20mm (variation of the outer end of the grip).
3. The factors that affect whether the clutch can be separated completely are as follows.
(1) clutch platen must have enough travel. The length of several springs and compression force should be consistent as far as possible, to ensure that the platen can be parallel movement, so that the gap between the clutch disc and the friction plate uniform.
(2) the flatness of clutch disc and friction disc should be small. The flatness of the clutch disc shall not be greater than 0.1mm, and the flatness of the friction disc shall not be greater than 0.15mm. Can be placed on the platform or glass inspection with a feeler.
(3) the teeth of the clutch disc must be able to slide undamped between the slots of the clutch housing. If the use time is longer, because of the groove on the shell indentation and block clutch disc sliding, should replace the clutch shell.
4 motorcycle clutch for oil bath type, in the case of lack of oil, clutch disc will burn. Should press the regulation of manual so, add regularly or change lubricating oil.
5. When adjusting the free travel of the clutch, adjust the adjusting screw of the ejector of the gland first, so that the clearance between the ejector and the platen is as small as possible, but it cannot contact with each other and force (by feel); Then adjust the free stroke of the grip.
1. If the braking distance exceeds the specification, remove the brake shoe and check the contact area between the brake shoe and the inner diameter of the brake hub. It is allowed to polish the brake shoe surface with a fine file and sandpaper, so that the contact area between the shoe surface and the brake hub is not less than 80% of the total area, and keep the shoe surface and the hub surface clean without oil pollution.
2. Brake shoe surface should be replaced during general overhaul. The allowable minimum thickness of hoof surface is generally specified as 1.5 ~ 2mm. When deep wear marks are found on the inner surface of the brake hub, the thickened brake shoe surface can be changed after turning.
3. Generally, the free travel of the front brake grip (change of the outer end of the grip) is 10 ~ 20mm, and the free travel of the rear brake pedal is 20 ~ 30mm. The wheels should be able to rotate freely without braking.
4. When frequently using the brake (such as downhill), the brake temperature will be very high, should stop in time to cool down, otherwise easy to burn the hoof surface. Driving in rainy days, brake force decreases after brake water, should drive at a low speed.
Pay attention to the shape of the piston. The piston of the two-stroke engine has a ventilation port, which is very rigid and easy to deform. So maintenance and disassembly, must be handled with care, do not hit with a hammer; When installing the piston pin, gently push it with your hand. If you cannot push it, heat the piston to 100℃ with boiling water, and then install the piston pin. Conditional also can put piston pin inside freezer, wait for piston pin to be installed again after cooling. Be sure to apply oil to the piston pin surface before installing it.
2. When installing the piston, please pay attention to check the offset cylinder. First do not install piston ring, put the piston into the cylinder, make it in the normal working dead center position, observe the direction of the piston pin, the gap between the piston and the cylinder is uniform. Check with the feeler, if the gap between right and left is more than 0.05mm, cylinder knocking will occur, the piston will not be used.
3. Pay attention to carbon removal. Remove carbon from piston top, piston ring groove and piston skirt every 3000km. Do not use a metal knife when cleaning, so as not to scratch the surface of the piston. You can use gasoline to soften the carbon bubble and then use a wooden pick to remove, conditional can be placed in the water glass piston boiled, carbon is easier to remove.
4. If the temperature of the engine increases, the speed of the car will slow down after the throttle is increased, the piston may be pulled. At this time should immediately stop driving, remove cylinder head inspection. If piston does pull slightly, can use fine whetstone or fine sandpaper burnish to pull, reoccupy gasoline is cleaned clean. Continue to drive, should first drive at a low speed, check the engine temperature change, if not overheating, then normal use.
Motorcycle piston ring
1. Piston ring is the main seal of engine combustion chamber, and its sealing surface includes: external surface, upper and lower side and open end face, the requirements of the three faces are as follows.
(1) the light leakage of the outer circular surface and cylinder body should be small. The ring can be put into the cylinder body, the middle of the cardboard block with light inspection, if the open end on both sides of light leakage, then the ring can not be used.
(2) the upper and lower sides should be flat without bruises. Before loading the ring into the piston ring groove, it should be placed on the glass to check whether the ring is warped. If it is warped, it cannot be used. Then the ring into the ring groove, try to see if it can be flexible rotation. Ring groove and ring shall have a gap of 0.01 ~ 0.02mm.
(3) put the ring into the cylinder body to check the opening gap, whose value should be between 0.05 and 0.15mm. Too small file can be used to repair, too large can not be used
2. Special tools or sharp nose pliers should be used to remove and install the piston ring, so as not to break the piston ring. The ring should be coated with oil before loading the ring groove, each ring should be installed in the original ring groove, can not be arbitrarily changed position. 3. If the opening clearance of the ring is found to be more than 0.5mm, it shall be replaced in time to prevent the gas from tampering with the crankcase and damaging the bearing.
1. The breaker is the component that controls the ignition time. The fixed and moving contact surfaces of the breaker should be kept parallel and completely in contact. The surface of the two contacts should be kept clean and free of grease and impurities. The linoleum shall be lubricated and oil shall be added every 1000km. The amount of oil shall be appropriate and the contact shall not be contaminated.
2. If the ignition found in the driving is not correct, it may be the electrical contact is contaminated or ablative caused by the application of whetstone or sandpaper polishing. Sometimes broken electrical contact loose will cause improper ignition, which should be removed and riveting. If it is found that the contact of the broken electrical appliance is often ablated, the capacitor is damaged and should be replaced.
3. If the engine is found to be weak in running, it may be caused by the too small gap between the contact points of the broken electrical appliances. Check contact clearance with a feeler to keep it between 0.3 and 0.4mm. After adjusting the platinum gap of the contact point, be sure to re-adjust the ignition time.