The cause of carbon buildup in the engine
The engine is powered by a piston moving down, drawing a mixture of gasoline and air into the cylinder. The upward-moving piston compresses the oil and gas into a highly combustible gas.
The source of the power -- the mixture, must go through the intake valve into the combustion chamber, a small part of the gasoline will adhere to the intake valve, in the event of high temperature engine, gasoline can not burn complete hydrocarbons, paraffin, gum will be burned into adhesive carbon.
A method to clean up the carbon buildup in motorcycle engines
1. The oil line, carburetor, combustion chamber, valve seat bonding surface and exhaust passage can be cleaned with the fuel system cleaner.
Specific usage, add an appropriate amount of cleaning agent in the gasoline tank, fully stirred can be put into use, the proportion is about 2% of the fuel capacity (generally 5000 ~ 10000 km should be cleared once).
2. Carbon accumulation in engine interior and oil passage.
The internal engine cleaner can be added to the crankcase at 5% of the oil capacity. After driving for 1 hour, it is discharged with dirty oil in engine condition (usually 15,000-20000 km should be cleared once).
This is a method of using a scraper to remove carbon deposits. Use scraper, screwdriver, old saw blade and bamboo skewer to remove carbon. For the carbon accumulation in the combustion chamber of the cylinder head, the sawblade with a semi-circular front end can be used to remove the sawtooth.
For the cylinder body vent carbon can be removed with a bamboo tip or screwdriver, but be careful not to damage the inner wall of the cylinder. The accumulated carbon in the piston ring groove can be scraped off with the broken piston ring of the same type.
Be careful not to scratch the piston ring notch.
After the carbon is removed, the scratches on the piston ring groove can be rubbed off with metallographic sandpaper, and finally all the parts can be cleaned with kerosene or gasoline (preferably kerosene, because of its strong permeability) before assembly.
Relatively large parts can be soaked with trichloroethylene for tens of minutes before cleaning, because trichloroethylene can dissolve carbon in the gum and asphalt and other viscous substances, can make the remaining carbonaceous compounds and metal compounds become brittle and easy to remove.
Smaller parts can be immersed in 80℃ ~ 95℃ chemical wash solution for 2 ~ 3 hours, after it softened, then transferred to hot water with a brush to remove residual carbon, and finally dried with compressed air. For castings and steel parts, oil shall be applied to the surface of the parts after removing the carbon deposit and cleaning to prevent corrosion.
It must be emphasized that caustic soda (NaOH) has a corrosive effect on aluminum, so caustic soda containing detergent should never be used to clean aluminum parts.
Because at present most of the motorcycle engine cylinder head is made of aluminum alloy material, we hope that you give careful treatment, can not be disposed of at will, so as not to bring unintended consequences.