Carburetor supplier | Causes of carburetor back injection:
(1) The intake valve clearance is too small. Thermal expansion and cold contraction lead to thermal expansion, so that the intake valve is not closed tightly and leaks air, causing the combustible mixture pressure in the combustion chamber to return to the intake pipe and enter the carburetor, forming a reverse jet flow.
(2) Exhaust valve clearance is too large. The exhaust valve cannot remove waste in time, resulting in the reverse jet flow of high-pressure exhaust gas when the intake valve is opened at the end of the exhaust stroke.
(3) The exhaust cam is severely worn. When the exhaust cam is severely worn, the exhaust valve cannot be fully opened in time to complete the exhaust during the exhaust stroke, resulting in a de facto gas distribution inaccuracy, resulting in back injection of the carburetor.