Mower engine and valve repair problems

by:Jiali     2020-06-17
The lawnmower is mainly used in garden decoration pruning, grass greening pruning, city streets, greening spots, pastoral pruning, field weeding, especially grass fields and grasslands in the park, football fields and other grass fields, private villa gardens, and agriculture, forestry and animal husbandry The repair of the site vegetation and other aspects can also be used during the autumn harvest. Today's commonly used lawn mowers are gasoline lawn mowers, which are widely used, mainly used for lawn trimming and beautification in park grass, green belts, factory grass, golf courses, home gardens, grass, orchards and other places. Today I will mainly talk about the maintenance of lawn mower engines and valves. 1. Reasons for unstable operation of lawn mower engine The throttle is at the maximum position and the damper is open; the spark plug wire is loose; water and dirt enter the fuel system; the air filter is too dirty; the carburetor is improperly adjusted; the engine fixing screw is loose; the engine crankshaft is bent. Remedy: lower the throttle switch; press the outer line of the spark plug; clean the fuel tank and refill with clean fuel; clean the air filter or replace the filter element; readjust the carburetor; check the engine fixing screw after the flame is turned off; correct the crankshaft or replace the new shaft. 2. The reason why the lawn mower engine cannot be turned off The installation position of the throttle wire on the engine is inappropriate; the throttle wire is broken; the throttle movement is insensitive; the flameout wire cannot be touched. Remedy: reinstall the throttle line; replace with a new throttle line; drip a small amount of engine oil to the active position of the throttle; check or replace the flameout line. 3. What should be paid attention to before the lawn mower is stored? Matters that should be noted before storing the lawn mower: When the lawn mower is stored for more than 30 days: First, drain the fuel from the fuel tank and start the gasoline engine until it shuts down due to exhaustion of fuel. Secondly, change the engine oil. In the hot engine state just stopped, first release the engine oil in the crankcase, and then add new engine oil to the appropriate scale according to the recommended grade. Third, remove the spark plug, drip 5-10 ml of engine oil into the cylinder, turn the crankshaft several times, and install the spark plug. Fourth, clean the dust and debris around the cutter head, machine body, cylinder body, cylinder head fins, air hood, grille and muffler, and store them in a dry and cool place. 4. How to adjust the maintenance valve of four-stroke mower? The maintenance of four-stroke lawnmowers often encounters the question of valve adjustment. How to adjust and how much to adjust is a question often encountered by new maintenance lawnmower maintenance personnel. The task principle of the valve assembly of the four-stroke lawnmower is similar to that of the gasoline engine, and the device and adjustment method are also similar. However, because the power of the lawnmower is relatively small, the accuracy requirements of the adjustment will be higher. The mower valve adjustment is as follows: In terms of valve device: It can be seen that there is a positioning point on the mower cam teeth and the mower crankshaft teeth. When the positioning points of the crankshaft and cam are right, then push the piston to the top. At this time, the magnetic flywheel points directly upward, and the magnetic flywheel and the high-voltage package are just close to the distance between the magnet and the turn, and the connection is the adjustment of the valve. At this time, just adjust the valve and the upper rocker arm to fit tightly. In fact, the gap between the valve and the upper rocker arm is 0.02±0.005 mm. This practice only needs to be just pasted. The gap is due to the principle of thermal expansion and contraction of the object, and it will be in close contact when launching the machine task. The tightening power of intake valve and exhaust valve changes as follows: (1) The gap is too large: after the intake and exhaust valves are opened late, the intake and exhaust time is extended, the opening height of the valve is reduced, the normal valve timing is changed, and the engine is exhausted due to lack of intake air and exhaust The decrease in power also increases the impact of parts of the valve train and slows down wear. (2) The gap is too small: after launching the machine task, the parts are heated and contracted, the valve is pushed open, the valve is not closed tightly, the air leakage is formed, the power is reduced, and the sealed surface of the valve is seriously carbonized or burned, or even the valve impact piston. (3) The gap of the exhaust valve is larger than that of the intake valve due to heat shrinkage, so the gap is larger, and it is actually about +0.005 mm than the intake valve. Finally, as long as the positioning points of the crankshaft and the cam match, valve adjustment is not difficult. It only takes a few more adjustments to get started. The above explanation about the lawn mower engine, valve maintenance and storage issues, I hope it can help everyone. Weeding with a lawnmower, the effect is better when weeds grow to 10-13 cm. If the weed grows too high, it should be done in two steps, first cutting the upper part, then cutting the lower part. When using the lawn mower, hold the handle with both hands and maintain a certain inclination to the side of the fruit tree, so that the cut weeds fall as close as possible to the fruit tree. Opening the medium speed throttle and advancing at a uniform speed can save fuel consumption and improve work efficiency.
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