Trouble phenomenon: During the operation of the engine, there is often a rhythmic “click, click, click” sound on the upper part, and it increases with the increase of engine speed. The fire test does not change the sound. Listen carefully, it is obvious that after listening to the tight sound, there is a slighter sound, or a continuous sound of “sand, sand, sand”.
Cause of failure: This sound is caused by too soft or broken valve spring.
Troubleshooting: When diagnosing, you can remove the cover of the gas station chamber, start the engine, and run the engine at medium speed. Observe the working condition of the valve by auditory or visual observation to determine the sounding part. If the valve spring is not broken, you can use a screwdriver to pry up the spring , Listen carefully to the change of the sound, if the sound disappears or weakens, the valve spring is too soft. To get rid of this noise, just replace the broken or too soft spring. If there is no spare part, the spring seat can be cushioned for emergency use; for the broken spring, the two sections can be reversed. Make the planes face each other and use it in emergency after installation. If the spring is broken or several knots and cannot be used continuously, the valve adjusting screw of the cylinder can be removed to keep the valve closed and the cylinder to stop working.