8-piece compression tester kit for gasoline engine cylinder compression gaugeAUTO COMPRESSORA problem with the engine is indicated when1. Low pressure at first stroke and cumulative pressure per stroke is only 10-20 PSI, which indicates that the valve is stuck or the valve seat is burned2. the pressure of one or all cylinders is low, a small amount of oil enters the cylinder, check the piston ring or cylinder wall is damaged, or the oil blocks the piston ring around the small leak, if the result is still very low, the problem is in the valve or the head gasket, if the increase is small, the piston ring, the valve or the head gasket is defective, or all three may be defective.3, higher than normal pressure is due to carbon overload of the cylinder.4, the cylinder has been repaired, a new piston ring has been installed, if the reading is low, it may be due to the piston ring installation has problems.+ productPressure gauge test range: 0300PSI / 02000kPaLength and thickness: 7.2 cm (3)Subject Size: M18x1.5, M14x1.25, M12x1.25, M10x1.0Connector Length: 6 (14.4)Hose length: 18 (43cm)open the carburetor throttle fully to see if the result is the same.When the engine is started, firmly press the rubber refractory cone of the pressure gauge against the spark plug hole.Drive the engine with the starter until it goes through all 4 compression processes, with a slight pulse in the measured value occurring on each compression stroke, noting the readings on the first and fourth strokes. Ensure the battery is fully charged, the starter is in good condition, and the engine is running at a normal speed; using the starter too slowly may cause incorrect results.FeaturesStart the engine until it reaches normal operating temperature.Loosen all the spark plugs one or two turns and crank the engine with the starter (without letting it start) for 5 to 10 seconds, this helps disperse the dust around the base of the spark plugs and prevents it from falling into the cylinder.open the carburetor throttle fully to see if the result is the same.